Glow wiring issue (1 Viewer)

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I am hoping a wiring guru will see this...

Quick background:

2H in a FJ62, glow wired to the defunct EFI circuit, glow is operated by using a spare defrost switch, timer light is from a HJ61.

This has operated with no issue for a long while...

Two nights ago, I climb in, flick the glow switch...and nothing. The switch light does not come on, the (20 second) timer light does not come on, no faint relay click, no movement in the voltimeter needle, no glow. Luckily, the truck was still warm and it started right up anyhow, no problem.

The next morning, different story. 50 degrees, took pouring near-boiling water over the fuel lines and glow plugs to get it started. No fun.

I popped the hood to see what I could see and jiggled wires, made sure nothing came unplugged. I saw nothing. Went in the cab and looked at the fuses. Yup, blown.

Now, keep in mind that the glow (again) was powered off of the old EFI circuit (since I no longer have EFI, it was a vacant spot on the fuse panel), which was a 15 amp fuse. The fuse was not changed (still 15 amp.). I popped another 15 amp fuse in there and immediately upon flicking the glow switch, it popped.

I put in a 20 amp fuse...same thing. I had no more 15 or 20 amp fuses and said "what the hell...." and threw in a 30 amp fuse.

Well, that keeps both the timer light and the switch light on and the fuse does not pop, but I still have no glow.

I was not the one to set up my wiring, that guy is unavailable, and I need some troubleshooting help here.

Do I check my relay, and if so, how? What amp fuse SHOULD I be putting this glow circuit?

What else might be the problem?

Let me know what more info is needed to go on to figure this out; if I know, I'll say so, but I know NOTHING about wiring and and intimidated by it, frankly.

I have accidentally kept the glow button in the ON position for 5+ minutes a couple of times, months ago, but that didn't seem to burn anything out. I have not done that in a while.
 
Oh, one other thing. Ever since this system was first set up, the glow timer light will sometimes not come on (though the glow is...evidenced by the easy start), but if I flick the switch on and off a few times, the glow timer light usually will come on, and will stay on for the 20 seconds it is supposed to.

Don't bother talking to me about solenoids ammeters, etc.; that's Greek to me. I can handle fuses, a fusible link, and MAYBE replacing my relay.
 
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The glow system can draw way more than 15A under load. It should be powered by a solenoid under the hood and close to the glow bus. The solenoid can be triggered by your timer circuit.

~John
 
Ya see? I am indebted for the help, and thank you, per usual, John, but this is the "Greek" to which I referred.
 
Just read a little more, and it would be better if you used a momentary switch rather than one that you have to remember to turn off.

If things are not working now, but they were, then perhaps some wiring or some contacts in a switch or relay have died.


~John
 
Just read a little more, and it would be better if you used a momentary switch rather than one that you have to remember to turn off.

If things are not working now, but they were, then perhaps some wiring or some contacts in a switch or relay have died.


~John

Yeah, I know, I've been told that...

I will find somebody to test my relay/solenoid, switch, and whatever else needs to be looked at. I hate electrical s***.
 
I wish there was a switch that would automatically switch off when the glow timer light went out...

Holding a push button for 20 seconds got old... Same would be true for a momentary switch.
 
OK. No voltage at the bus. I went immediately to the Glow relay
IMG_0234.jpg


and unplugged the bottom one of these two barrel/cylinder connections.
IMG_0237.jpg


with the glow plug switch in the off position, I tested the female end as you can see,
and nothing. Switch on, I get 12+ volts.

IMG_0240.jpg


Great.

I go to unplug the other cylinder/barrel connector...and can't. Seems like the connection is melted (soldered) together inside.

Ah...

OK, now what?
 
cut the plug out, join the wires and re-test.

~J.
 
Yeah...I was planning on that.

This morning I just jumped the bus straight from the battery, and my 6 year-old started her up. Interestingly, this caused her to start up MUCH more smoothly than usual, as if I am not ever really getting 12v to the bus, and thus a weak glow...

I am beginning to think my entire harness needs to be redone (from scratch), as my doorlocks, windows, headlights...everything electrical, seems to be weak.

I had to run a new line (with a Ford relay) to my starter a while back because it was getting only 7v.
 
your fuse size should be determined by the wiring. the point of a fuse is to protect stuff (like your melted connector)

if all of your electrical is weak, I would first check the ground cable to the battery. If that is corroded, nothing else will work optimally. One easy check is to start the vehicle and turn on lights, stereo etc

Check voltage at various points

then connect a jumper cable from the battery ground to a clean point on the frame

recheck voltages
if they are higher, then your ground was the culprit
 
cut the plug out, join the wires and re-test.

~J.

Did that. I actually found one more fried connector and cut that out too (the one within a couple of inches from the battery terminal).

I get 12+ volts to the relay, 12+ volts at the timer (under my dash), 12+ volts at the switch (and I tried using two other switches), and the fuse is not a 30 amp and it does not pop. The timer light works, and the switch works. No juice at the bus, on either end. A wire straight from the battery to the bus works like a charm, so it isn't the glow plugs themselves.

I suppose the only thing left that could be bad is the relay itself, right?

I would just replace the relay with a Ford (or other) one, but I want to keep the timer in the circuit, and I am not sure a Ford (or other) relay would have a provision for that. I don't want to pay for the 2H glow relay ($100 at Specter).

John, got a 12v 2H glow relay? If so, how much $?


your fuse size should be determined by the wiring. the point of a fuse is to protect stuff (like your melted connector).

if all of your electrical is weak, I would first check the ground cable to the battery. If that is corroded, nothing else will work optimally. One easy check is to start the vehicle and turn on lights, stereo etc

Check voltage at various points

then connect a jumper cable from the battery ground to a clean point on the frame

recheck voltages
if they are higher, then your ground was the culprit

I am going to replace my ground (to the motor and to the body), and sand the contact points, just because. It will be a cheap way to rule out a bad ground. I will also clean the glow plug relay ground as well.

Any other suggestions?
 
I'll bet you fried the relay. If you are a little creative and not too worried about stepping outside the norm, take the relay apart and file the contacts clean and see what happens.
 
Another clue to reinforce the fried relay theory... The yellowish insulation that surrounds the copper coil in the relay...mostly missing, some melted and charred. Seems like by leaving the switch on too long, too much heat built up in the relay and toasted it. The wires all seem intact though, but I am betting you are right. Once the relay failed, I suppose it would no longer prevent too much amperage from going through the circuit and thus fried the fusible links/connectors and blew the fuse...
relay.jpg
 
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Actually there is only a laquer insulation on coils. The "yellow" insulation is not supposed to be there. Try putting 12v to the coil and see if the contacts close. That would be the contacts in front of your thumb knuckle in the picture.

The relay does NOT regulate current. It is simply a switch with a high amp rating that is controlled by another switch, generally of a lower amp rating.
 
I would think that you could wire up a very simple relay circuit- there has to be an affordable solenoid/relay out there that can work for your needs.

Anyone know how much current the plugs pull? I thought that I remember reading 5A each, but that could be my imagination.
 
So, I bought a starter solenoid for a 1990 Ford F250 diesel. $15. Nice and heavy.

It looks like this:
41602ZXZD3L.jpg



This should work, right?
 
should work fine
run the big wire to the big terminals
the little wire to the little ones
 
OK sand cruiser, let's get a little more specific...

Here's my wiring. Ground goes to the body, white on black and red on black wires go to my glow timer and switch...where on the new Ford relay do I hook them up, "S"? Does one go to "I"?

B obviously goes to the fusible link (I have a 30 amp), then to the battery +

Then, M would go into the harness (blue on black, dead center of first photo) and comes out close to the firewall and then connects to the back of the glow bus, I suppose.
photo3-1.jpg


So imagine "to relay" above is the new Ford solenoid, here:
photo2.jpg


And the pattern in that diagram is:

-----M

I-----------S

-----B
 
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