HJ47 welcome here? (2 Viewers)

[Henry James the 47th]

Made some more progress on the wiring:

-discovered that the Optima battery was far from charged and that was why the starter solenoid was not activating. The battery is on trickle charge now and should be looking decent by tomorrow morning.

-found that I hadn't connected a wire that ran to the rear of the truck, sorted that out and now all the lights, except the headlamps, operate. Still working on the front marker lights, which come on as soon as the key enters the ACC position. Somehow power from that circuit is getting to the marker lights and I haven't tracked it down yet.

Another difficulty occurred yesterday when I put power to the glow circuit: the little wire coil in the Glow plug controller, visible through the mesh screen in front of it, glowed cherry red. As I had never seen one operate, I initially thought "great, it works!" - then after 3 second's operation, the wire coil abruptly snapped in half.

I learned that the reason why I fried the glow plug controller yesterday is that I forgot to connect a little wire across the junction where the line comes in from the glow relay to the controller, so that left the controller wired in series with the glow plugs, instead of in parallel as it is supposed to be. My bad. I had planned to do it, but omitted to do so. As the controller was hooked up in series it received the full jolt of current fromt he relay, instead of the distributed load it should have received. I learned from John at E4 that the controller coil only glows a dull red, not cherry red, so now I know what to look for next time I put current to one.

It looks like I can get another one of these little controllers though, either from Oz or Japan.

My multimeter crapped out so I need to get another tomorrow am.

The remaining wiring issues to solve:

-the ACC power going into the front marker lights problem
-the brake warning light circuit not coming on issue
-sedimenter circuit light not coming on fiasco


Also, getting the starter motor to turn the engine over is a step I need to take.

I think I need to go the whole way here, and get the engine running if I can, before pulling the harness out for wrapping. I can get the alternator bench tested to see if it is operating correctly as well. Ditto for the starter motor. I switched the internals from the 12v. one I had into the 24v. one's housing. So I'm not 100% sure how well, or even if, the starter works properly. With a single battery and a 6 cylinder to crank, it needs to perform well.

This wiring diagnosis phase is stressing me out big time, but this is a good opportunity as well.

 

[lostmarbles]

.....Another difficulty occurred yesterday when I put power to the glow circuit: the little wire coil in the Glow plug controller, visible through the mesh screen in front of it, glowed cherry red. As I had never seen one operate, I initially thought "great, it works!" - then after 3 second's operation, the wire coil abruptly snapped in half.

I learned that the reason why I fried the glow plug controller yesterday is that I forgot to connect a little wire across the junction where the line comes in from the glow relay to the controller, so that left the controller wired in series with the glow plugs, instead of in parallel as it is supposed to be. My bad. I had planned to do it, but omitted to do so. As the controller was hooked up in series it received the full jolt of current fromt he relay, instead of the distributed load it should have received. I learned from John at E4 that the controller coil only glows a dull red, not cherry red, so now I know what to look for next time I put current to one.

Hi HJ.

Firstly - The coil in mine glows bright orange (hotter than red heat). And mine didn't even "snap" after being left glowing for 20 minutes or so (when I had the steering column apart and didn't realise I had knocked the ignition switch into the glow position)!

So I don't understand why yours should "snap" on "red heat" unless it was already damaged or under stress somehow.

Do other peoples' coils glow "bright orange" like mine or "dull red"?

Or does this colour indication depend on the model of vehicle?



Secondly - We know the current flow through a load is proportional to the voltage across it. And when loads are connected in parallel across a power supply they each receive the "full supply voltage" whereas when they are connected in series across the same supply they share that voltage. (In series, each load receives a SMALLER voltage that together add up to the supply voltage.)

I'm at work at the moment so I can't check my wiring diagrams (to see how your/my coil should be wired into the circuit) but I suspect you have mistakenly transposed "in series" and "in parallel" in your post above? Because it doesn't make sense to me. (When "in series" your coil should have been less likely to burn out - Shouldn't it?)

 

[Henry James the 47th]

Hi HJ.

Firstly - The coil in mine glows bright orange (hotter than red heat). And mine didn't even "snap" after being left glowing for 20 minutes or so (when I had the steering column apart and didn't realise I had knocked the ignition switch into the glow position)!

So I don't understand why yours should "snap" on "red heat" unless it was already damaged or under stress somehow.

Do other peoples' coils glow "bright orange" like mine or "dull red"?

Or does this colour indication depend on the model of vehicle?



Secondly - We know the current flow through a load is proportional to the voltage across it. And when loads are connected in parallel across a power supply they each receive the "full supply voltage" whereas when they are connected in series across the same supply they share that voltage. (In series, each load receives a SMALLER voltage that together add up to the supply voltage.)

I'm at work at the moment so I can't check my wiring diagrams (to see how your/my coil should be wired into the circuit) but I suspect you have mistakenly transposed "in series" and "in parallel" in your post above? Because it doesn't make sense to me. (When "in series" your coil should have been less likely to burn out - Shouldn't it?)

Hi Tom,

Thanks once again for your comments. i especially appreciate your description of the controller and the color the coil turns when power goes to it.

As for the difference between in parallel and in series, I am by no means whatsoever knowledgeable about electrical systems, so am definitely unsure of my conclusions. I'm trying to make sense of the situation with the knowledge I have at this moment, scant as it is.

Still, I am pretty sure that I had the controller wired originally in series, and the following link would seems to confirm that:

Series and Parallel Circuits

To explain: as originally wired, the power lead went from my fusible link directly to the glow plug relay. When the relay receives current to its switch from the ignition barrel, the power from the battery is shunted to the output wire. This wire then went all the way to the controller on my dash, and then returned to connect to my glow plugs. Thus the controller was first in a series, though it is also true that the second leg of that series, the glow plugs, are themselves wired in parallel. This fact would seem to be confirmed by the link above as well,

"A parallel circuit is a circuit in which the resistors are arranged with their heads connected together, and their tails connected together. The current in a parallel circuit breaks up, with some flowing along each parallel branch and re-combining when the branches meet again. The voltage across each resistor in parallel is the same."



So, what I should have done is to have the output wire from the relay go to both the controller and across to the glow plugs, thus putting the controller into parallel (however, the difference being that the controller is not wired into the same ground circuit as the glow plugs - here I am most definitely a bit confused).



Here's another key piece of information: I am not using the exact type of glow plug relay that Toyota put into the truck for these systems. They used a relay with a pair of shunts inside, so that the input power would be sent out through two separate lines when the current came to the relay from the ignition switch.



Since the correct type relay is no longer available from Toyota, and I didn't want to wire up a 25 year old relay, I went with a newer one with the four wire system (power in, power out, one wire for the switching power, and one wire for ground). I reasoned that I could connect up the controller to the single wire output, providing I connected it in parallel, as it would seem to be when using the correct relay. This may be a completely erroneous idea on my part, and there is already one dead controller to show for it. Thought the FSM wiring diagram does not show a resistor inside the relay for the output to the glow controller, I assumed that where they went with branching the input power though two switches into two outputs there was no difference in the output wire voltage. I may be wrong about that, but where on earth can anyone find accurate information on such a topic?



I do appreciate any advice or commentary that folks want to offer - this is a head-scratcher for sure.

 

[lostmarbles]

.......To explain: as originally wired, the power lead went from my fusible link directly to the glow plug relay. When the relay receives current to its switch from the ignition barrel, the power from the battery is shunted to the output wire. This wire then went all the way to the controller on my dash, and then returned to connect to my glow plugs. Thus the controller was first in a series, though it is also true that the second leg of that series, the glow plugs, are themselves wired in parallel. This fact would seem to be confirmed by the link above as well,
So, what I should have done is to have the output wire from the relay go to both the controller and across to the glow plugs, thus putting the controller into parallel (however, the difference being that the controller is not wired into the same ground circuit as the glow plugs - here I am most definitely a bit confused).

Here's another key piece of information: I am not using the exact type of glow plug relay that Toyota put into the truck for these systems. They used a relay with a pair of shunts inside, so that the input power would be sent out through two separate lines when the current came to the relay from the ignition switch.

Since the correct type relay is no longer available from Toyota, and I didn't want to wire up a 25 year old relay, I went with a newer one with the four wire system (power in, power out, one wire for the switching power, and one wire for ground). I reasoned that I could connect up the controller to the single wire output, providing I connected it in parallel, as it would seem to be when using the correct relay. This may be a completely erroneous idea on my part, and there is already one dead controller to show for it. Thought the FSM wiring diagram does not show a resistor inside the relay for the output to the glow controller, I assumed that where they went with branching the input power though two switches into two outputs there was no difference in the output wire voltage. I may be wrong about that, but where on earth can anyone find accurate information on such a topic?.....

Hi HJ.

We obviously do indeed share the same understanding of what constitutes either a "series" or a "parallel" circuit. (And I still stand by my statement that your coil was at LOWER risk of burning out when it was connected in series.)

I've been searching threads and this thread (which you were involved in) was of particular interest to me:

https://forum.ih8mud.com/diesel-tech-24-volts-systems/200264-glow-relay-indicator.html

In it, Amaurer says his terminal S was a "dummy" (connected to nothing). So therefore having your dash coil in series with the "parallel-wired glow plug combination" is correct as far as I can make out.

This is the diagram Amaurer posted too:



So if S is connected to nothing - Then the way I read the diagram (and assuming your is wired similar to mine/Amaurer's) the "dash glow coil" must/should indeed be in series with the "parallel-wired glow plug combination".

And since your vehicle is 6 cylinder (Am I right?) there are 2 extra glow plugs compared to mine and that should mean higher current for your "dash coil". (Cos adding extra resistors in parallel gives the "parallel combination" a lower overall resistance.) ------- Which raises the question of whether a 6 cylinder engine would have a "dash coil" of a different rating (than a 4 cylinder diesel) to cope with the higher voltage it receives (due to the effect of the two extra glow plugs)!!!!!

 

[lostmarbles]

....So, what I should have done is to have the output wire from the relay go to both the controller and across to the glow plugs, thus putting the controller into parallel (however, the difference being that the controller is not wired into the same ground circuit as the glow plugs - here I am most definitely a bit confused). ..

AS you can see from my last post, I don't follow this bit HJ. Are you trying to mimmick that wiring diagram above (posted by Amaurer) while assuming that terminal S is actually getting fed 12V (+Ve) internally by the relay? If so, then your "dash coil" would get 12 +Ve on both sides. Therefore, since there is no "potential difference" across it, it would do nothing. (It wouldn't glow because there would be no voltage across it.) And remember that Amaurer says terminal S is a "dummy". (Well - my enterpretation of what he said. Please protest vigorously if I'm misquoting you Amaurer . )

Here's another key piece of information: I am not using the exact type of glow plug relay that Toyota put into the truck for these systems. They used a relay with a pair of shunts inside, so that the input power would be sent out through two separate lines when the current came to the relay from the ignition switch.

Since the correct type relay is no longer available ...I went with a newer one with the four wire system (power in, power out, one wire for the switching power, and one wire for ground). I reasoned that I could connect up the controller to the single wire output, providing I connected it in parallel, as it would seem to be when using the correct relay. .... Thought the FSM wiring diagram does not show a resistor inside the relay for the output to the glow controller, I assumed that where they went with branching the input power though two switches into two outputs there was no difference in the output wire voltage. I may be wrong about that, but where on earth can anyone find accurate information on such a topic?....

Sorry but I can't get my head around this to work out exactly what you've done. Perhaps if you post a wiring diagram of your set-up so we can compare it with Amaurer's diagram?

 

[lostmarbles]

Hi again HJ.

Just looked up the Toyota EPC and it lists exactly the same "glow controller" (what I've been calling the "dash coil") for both the HJ45 and BJ40. (Part number 28550-46021 - 12V). Does an HJ45 have a 6 cylinder diesel???

And an HJ47 is listed as 28550-47040 (but then I seem to remember you went for the older/simpler glow system which hopefully is like my BJ40 or Amaurer's BJ42 and hopefully - like an HJ45 too?).

Not sure where this leads us because I never was very knowledgeable about other models of cruisers. (I try to concentrate my knowledge on my own model. The way I see it. - My brain has very limited storage capacity!!!!!)

So I guess what I'm saying (and I concede it may be of no help/interest to you anyway) is that if you have an 28550-46021 glow controller (now stuffed - I know), and if an HJ45 has a 6cyl diesel fitted, and if you are using the same glow plugs as an HJ45 (in your HJ47), then everything should be matched OK.

But since I don't know much about HJ45s or HJ47s - I'm probably just talking dribble.

 

[Henry James the 47th]

Hey Tom, thanks again for your insights. That wiring diagram picture your posted above from the other thread is very familiar, and was the system I originally was going to use. Trouble is, those type of relays aren't available any longer - at least not that i can find. So I had to go to a newer relay - around 1986. The only relays that seem to be non-obsolete from Toyota are the ones that work in the Superglow type of set up. I'm not using Superglow, but I do have the plan to use the primary relay from that system (there is a sub glow relay as well in Superglow systems).

The primary glow relay I am going to use has 4 wires: one is the heavy main power feed from the fusible link at the battery, the second is the output wire to the glowplugs, also a heavy wire, and then the two wires which comprise the switching wire and its ground. It seems like the simplest arrangement.

As for the idea that the terminal 's' in the drawing does nothing, that doesn't make any sense. it must do something (assuming correct operation). There is another drawing in the 1980 FSM for a BJ40, which uses a manual push button circuit for additional glows. The relay in that system has the same number of wires as the one you attached to your post. I'll post up pictures of it tomorrow (forgot to bring the FSM home).

I worked all day on the electrical system, and have some progress to report:

-the powering of the front marker lights through the ACC circuit has been sorted out.
-the BRAKE and FILTER warning lights have been made to come on at least (a ground wire connection to the body was missing). I have also tested and re-confirmed function of the sedimenter float switch.
-I discovered that the ignition relay was mis-wired and sorted that out
- I took the starter to a specialty repair shop in town. I managed to do several of the check tests in the engine repair manual, but didn't have an ammeter for no-load test so I took it to the shop - and learned that it's a 24v starter. I thought I had swapped some parts over between starters when I got the replacement engine, but obviously something went wrong somewhere. And now I know at least one reason that the starter wasn't engaging. Now i need to find out if i can convert it to 12 v. economically by changing a small part, or whether I have to get a new or used replacement. I wonder if there is much difference between an FJ60 starter and a BJ60 starter? If I need a new 12v starter it might have to come from Australia or Japan
-I still haven't been able to get the front headlamps to come on, and have tried for a few hours to find the cause. I'm not sure if the problem is with the relays, in the ground circuit, or what is going on. I'll keep digging away, and if I can't solve it, I'll have to call for help.

 

[lostmarbles]

...The primary glow relay I am going to use has 4 wires: one is the heavy main power feed from the fusible link at the battery, the second is the output wire to the glowplugs, also a heavy wire, and then the two wires which comprise the switching wire and its ground. It seems like the simplest arrangement.....

OK. So you've used just a simple relay (like the ones used everywhere for starters, spot lights, etc).

....As for the idea that the terminal 's' in the drawing does nothing, that doesn't make any sense. it must do something (assuming correct operation). .........

Yes. I tend to agree HJ.


Thinking out loud..........................
Ya know what would make sense to me? Since that wiring diagram in my post (Amaurer's diagram) shows a wire from the starter -- Well that wire must do something. Say if it were to control an internal relay that put power onto terminal S - Then you would have a little extra voltage fed to the glow plugs (because the glow controller would be bypassed) while you're turning the engine over (to glow them brighter right when they're most needed). That sounds like a good idea to me and I wonder if it is how it is all supposed to work. (Perhaps some of Amaurers glow relay internals had been removed by a nasty kiwi PO before he looked inside?)

So when the ignition key is in the "glow" position, terminals B and G would be connected. And when the key is in the start position, B and S would be connected ................... If you see what I mean. (That looks like a sensible way of doing things.)

There is another drawing in the 1980 FSM for a BJ40, which uses a manual push button circuit for additional glows. The relay in that system has the same number of wires as the one you attached to your post. I'll post up pictures of it tomorrow (forgot to bring the FSM home).....

I wonder if that button puts 12V +Ve onto terminal S?




PS. I still can't see that you caused the controller to fail from the way you wired it. If you made a mistake, I think it is more likely to have been your glow plugs being of too high wattage for the controller. (But then again - I would have expected your controller to glow much brighter than "dull red" if that had been the case.) Very puzzling!!

 

[Henry James the 47th]

oh yeah, "very puzzling" sums up this situation nicely

 

[amaurer]

HJ47, yes, I agree its puzzling, but I am absolutely sure the S terminal was disconnected. I can't, for the life of me, imagine why toyota did this; maybe its a test point, maybe they reused a harness, maybe they have a company policy about unused terminals, hell I don't know.

From my other thread:

Amazing!! I got the relay open, the BY line (terminal S) is attached to NOTHING! (There is no doubt about this, the S terminal is attached to the fiber baseboard in the relay with a rivet and no other connections. No solder, broken components, wires, etc.)

I had pictures, but, it figures, out of 500 pictures in my car folder, the relay pics have been lost.

It is possible to come to the same conclusion (the that S line does nothing) by inspecting the diagram, however:

If you assume that power gets switched to both the S and G lines, then you see that you have 12V on one side of the glow controller, and 12V on the other side of the glow controller!! If you have the same voltage on both sides, then no current will flow and it would never glow.

Likewise, if you assume the opposite, that S gets switched to ground, then you'd have 12V on one side of the glow controller, but 0V on the other side, and 0V at the glow plugs. This menas you'd never get any glow (and have 12 full volts across the controller, probably killing it)

Therefore, S terminal can't be positive, and can't be negative, so it must be neither. That is, it must be floating, unconnected to anything.

Firstly - The coil in mine glows bright orange (hotter than red heat). And mine didn't even "snap" after being left glowing for 20 minutes or so (when I had the steering column apart and didn't realise I had knocked the ignition switch into the glow position)!

So I don't understand why yours should "snap" on "red heat" unless it was already damaged or under stress somehow.

Do other peoples' coils glow "bright orange" like mine or "dull red"?

Or does this colour indication depend on the model of vehicle?

Mine glows dull red, and only the first two "loops" in the coil.

We should keep in mind that HJ47 has two extra glowplugs. The glowplugs are wired in a parallel bank (and the bank is wired in series with the controller), so adding two extra plugs decreases the effective resistance of the bank (by about 33%). The net result is that this will change the proportion of the voltage that is dropped by the glow controller. In my BJ42, I drop about 1.5 to 2V at the controller. I'd expect that HJ47 drops more due to the extra current, probably more like 3V.

This might point to the fact that there are different controllers, one for a 4-plug vehicle and one for a 6-plug. I don't know what'd happen if you applied 3V to the controller in a 4-cylinder truck, but it might blow it?

 

[lostmarbles]

.....It is possible to come to the same conclusion (the that S line does nothing) by inspecting the diagram, however:

If you assume that power gets switched to both the S and G lines, then you see that you have 12V on one side of the glow controller, and 12V on the other side of the glow controller!! If you have the same voltage on both sides, then no current will flow and it would never glow..............

Ah. I disagree with your first sentence (quoted above) Amaurer. Why does the "glow plug relay" have a wire originating from the "start terminal" on the ignition switch then? Is this just another "Toyota nonsense"?

Consider the idea that by putting the ignition key in the "start" position, a relay inside the "glow plug relay box" were to connect terminals B and S together. --- Sure this would render the "glow controller" inoperative but would that matter? The coil would still be glowing from its earlier current (cos it takes a while to cool down) and the starter motor won't be churning away forever. The way I see it, is that "chopping out the glow controller" in this way would tend to give the plugs a voltage boost at the time they most need it (during engine cranking). And remember that the battery will be under heavy load at this point (because of the massive current drawn by the starter motor) so trying to boost the power supplied to the plugs then would be doubly beneficial.

(Unless the battery is in top condition and of high CCA rating too - shorting out the controller in this way would probably simply "maintain similar voltage" rather than "boost voltage" anyway. This is because the battery voltage output would likely have fallen due to the combined effects of the massive starter-motor current draw-off and the battery's "internal resistance".)

But of course me saying all this is just silly conjecture - Because you found terminal S connected to nothing inside your "glow plug relay box".

Hell I'm tempted to rip into mine to try and confirm/refute your finding. Because I find this so interesting. But I fear damaging things and having to join HJ in his quest for replacements. (Perish the thought.)

But surely there must be someone out there with a "glow plug relay" already sitting in pieces in their workshop somewhere in the world that they can more easily investigate and photograph?

Hey. I know it sounds like I don't TRUST you Amaurer . (But I can't help it. Someone seriously afflicted with "40 series cruiser disease" trusts no-one!)

We need photographic evidence in this COURTROOM!

...This might point to the fact that there are different controllers, one for a 4-plug vehicle and one for a 6-plug. I don't know what'd happen if you applied 3V to the controller in a 4-cylinder truck, but it might blow it?

I considered this too Amaurer but the Toyota EPC ("electronic parts catalogue" for those that don't know - I HATE abrreviations too) says the same controller is used on an HJ45 as my BJ40. So that tends to counter that idea. (But I guess Toyota could have inserted something additional in the HJ45 circuit to compensate for this. -----More likely that they simply changed the glow plug specifications though).

....Mine glows dull red, and only the first two "loops" in the coil....

With all this talk of trouble with the glow controllers. I wish the heck I had never roasted mine for 20 minutes or more!

But I suspect the B engine has lower wattage plugs than the 3B (and other later engines). This would explain why I must glow my plugs for longer than most people and why excessive glowing is less likely to cause damage to my system. (Doesn't explain why my "glow coil" seems to glow brighter than other people's though.)

 

[amaurer]

Consider the idea that by putting the ignition key in the "start" position, a relay inside the "glow plug relay box" were to connect terminals B and S together. --- Sure this would render the "glow controller" inoperative but would that matter? The coil would still be glowing from its earlier current (cos it takes a while to cool down) and the starter motor won't be churning away forever. The way I see it, is that "chopping out the glow controller" in this way would tend to give the plugs a voltage boost at the time they most need it (during engine cranking). And remember that the battery will be under heavy load at this point (because of the massive current drawn by the starter motor) so trying to boost the power supplied to the plugs then would be doubly beneficial.

This is a pretty good theory, IMO. If I hadn't already peered into my relay, I'd jump on the bandwagon immediately, but I'm pretty confident in what I saw. However, its also a theory that we can test easily since my ignition switch is damaged and will allow me to start the car and keep the starter running. After work (in an hour), I'll start her up and leave the starter on for a while and see if my glow controller lights up. If it stays lit then I'm right, the S terminal does nothing. If it goes out while the starter is still running, then you're right, the Start position bypasses the controller via the S terminal.

Of course, I'm pretty damn sure about whats in the relay, lets bet a beer on it. You can also bet your ass that, if I'm wrong, I'll be tearing my own relay out tonight to get to the bottom of things!

But I suspect the B engine has lower wattage plugs than the 3B (and other later engines). This would explain why I must glow my plugs for longer than most people and why excessive glowing is less likely to cause damage to my system. (Doesn't explain why my "glow coil" seems to glow brighter than other people's though.)

Our glowing times seem on par. After about 20sec I have a dull glow on my two top loops and I can start just fine.

 

[amaurer]

This is a pretty good theory, IMO. If I hadn't already peered into my relay, I'd jump on the bandwagon immediately, but I'm pretty confident in what I saw. However, its also a theory that we can test easily since my ignition switch is damaged and will allow me to start the car and keep the starter running. After work (in an hour), I'll start her up and leave the starter on for a while and see if my glow controller lights up. If it stays lit then I'm right, the S terminal does nothing. If it goes out while the starter is still running, then you're right, the Start position bypasses the controller via the S terminal.

Ok, I did my little test and the glow controller says "lit" when the starter is running. As soon as its released it cools off in a couple of seconds, so I made sure to hold the starter on for a while to be sure it was actually getting redder and not just lingering.

I did notice that it dimmed a bit while the starter is running; drawing current away, no doubt.

My conclusion, therefore, is that the S terminal is not part of a starter-switch-glow-controller-bypass function, although it sounded good...

Also, I therefore remain extremely confident that my S terminal is unused. By inspection we know the relay does not switch S to B (12V). Similarly we know it doesn't switch S to GND. And now, via this test, we know it also doesn't switch S to G (controller bypass). We've run out of lines on the relay, none of the combinations are possible! (of course, there are the two lines to the relay coil from the ignition switch, but that makes even less sense than having an unused terminal)

 

[lostmarbles]

Ok, I did my little test and the glow controller says "lit" when the starter is running. As soon as its released it cools off in a couple of seconds, so I made sure to hold the starter on for a while to be sure it was actually getting redder and not just lingering.

I did notice that it dimmed a bit while the starter is running; drawing current away, no doubt.

My conclusion, therefore, is that the S terminal is not part of a starter-switch-glow-controller-bypass function, although it sounded good...

Also, I therefore remain extremely confident that my S terminal is unused. By inspection we know the relay does not switch S to B (12V). Similarly we know it doesn't switch S to GND. And now, via this test, we know it also doesn't switch S to G (controller bypass). We've run out of lines on the relay, none of the combinations are possible! (of course, there are the two lines to the relay coil from the ignition switch, but that makes even less sense than having an unused terminal)

Oh well. Damn.

I liked my little theory too Amaurer. And you've DESTROYED it!

OK ---- I concede defeat!!!

At least I've learnt that the glow plugs still get juice when the engine is being cranked. (I didn't know that before.)

And I'll have to study what we've all been saying a bit more (when I've got more time) to see if I have any other "words of wisdom to share". I'm all confused now and have to rush off to work.

 

[65-fj45]

I love watching this build, and by the way Happy B-day

 

[Henry James the 47th]

Thanks Mike

I've been intrigued by the recent posts and will post up some stuff tomorrow in response (just don't expect too much in the way of clarity )

 

[Henry James the 47th]

I was driving around today running an errand and thinking about the weird problem I was having with the headlamps- namely that there was power to the relay, the relay clicked, the headlamps were brand new, and I had gone over ever inch of the harness looking for a fault, to no avail.

The eureka moment came to me when I realized that I had made an assumption about the relay and how it worked. I had originally thought that since the relay is basically a glorified switch, that it didn't matter which way the power in and power out lines were connected. That's not true however. I got back to the truck this afternoon and reversed the two main wires going into the headlamp relay and voila, headlamps now work!!

oh yeah!


That leaves me with one less problem to solve. At this point, I have a brand new starter coming tomorrow, I've had the alternator bench tested and it seems to be fine.

The only non-operational electrical components is the light dimming rheostat, and the wiper motor. I'm feeling confident I can solve those issues.

So here's a picture of my truck from the front - I've started pulling the panels off and have moved them along to the bodywork department. I'm still working on the doors. The windshield frame and front bib will need little to no work. I have a box of parts that I will take for cad-plating pretty soon.

 

[Henry James the 47th]

Now then, on to the glow relay debate. In the first picture below, I have arranged three different Toyota glow relays side by side. The one on the left is a 24v. model from a 79-sish BJ40. The one in the middle is the original off my truck, and the one on the right is the sub-relay for a BJ60 with superglow.

In the second picture i have pulled the cover off my original relay. I was surprised to find that its internal condition was spotless, with no arcing of the contacts, dirt or damage.

The 'G', 'B' and 'S' terminal blades are arranged in that order from left to right. Let's see what the 'S' terminal connects to...

 

[Henry James the 47th]

Pulling the little plastic piece off the bottom exposes most of it to view. The 'S' terminal is connected to nothing but a rivet on the Bakelite platform (!). In pictures one and two you can see the tip of a pen touching the 'S' terminal blade.

I find this a little baffling. I took the relay to the local starter/alternator service shop, and the older fellow there didn't seem too bothered by that fact that one of the terminals was connected to nothing.

I gotta think there's a reason for this set up, but it escapes me.

The good condition of the relay however, and the fact that it will definitely work with my controller, is leading me to think that I might be best off going with the original, re-arranging my wiring as need be, and accepting the fact that if it dies several years down the road, I will have to reconfigure the wiring. I realized that I had my controller wired in correctly, but for some reason the relay cooked it in 3 seconds. I don't know the reason for this either, but with a couple of new controllers on order from Japan (3800-yen each), I want to avoid frying any more, so it seems wise to stick with the original relay.

Hey Tom (LostMarbles): could you do me a favor and check with Toyota New Zealand to see if glow plug relay 28610-68010 is available? If it is, I would like to order one, if you would help out with that by any chance? Let me know, thanks! If you have a paypal account that would be a simple way to transact this, otherwise, a money order from the post office would be no problem.

 

[Henry James the 47th]

And here's a picture from the FSM showing the relay arrangement that Toyota used with the BJ40, where the relay activated a warning light when the plugs were glowing. It seems there are tow separate relays inside, and indeed when I take the one I have apart, there are two separate solenoids. This was the factory version of the 'Wilson Switch', where there is a momentary switch on the dash to apply additional glows to the plugs after starting the engine (the momentary switch is illustrated at the upper right of the diagram).