Ok, Uncle. Turn signal/hazard problems

[capperdog]

This is a diagram that was already on-line in the Tech Links and I assume to be somewhere around late '76 to '78, since it has an ignitor. The wiring and wire colors didn't change much during that time. I did notice a difference between my '76 and my '78 diagrams, in that the wire from the F terminal of the Hazard Switch to the B terminal of the flasher is GO in '78 diagram and GW in '76 diagram. It's not labeled on this pdf diagram.

http://www.ih8mud.com/tech/pdf/fj40_wiring_diagram.pdf

You will find that switches and other devices, OEM and aftermarket, sometimes have different wiring colors than the harness itself, but typically the wires are in the correct locations in the plugs for the function. I just looked at a '76 column that I have out and the 6-pole plug for the turn signal switch has GY, GB, GO, GL, GR, and G wires. There is also a 4-pole plug with RY, RG, and WB wires and a single GW bullet connector. I'll have to do some additional research, since I've noticed that the wiring doesn't necessarily match the wiring diagram, as other noted earlier in this thread.

Yes I saw this diagram somewhere else last night. You see that the turn signal switch is only shown with the G\B Left, G\Y Right and G\L power from flasher. No other wires show at that switch and the other wire colors are not listed. This makes perfect sense, as those should be the only wires needed for left and right turn. I am baffled by my B\L showing 12 V at the switch but drops to 0 if a bulb is attached???? It makes me wonder if it is supposed to do that to trigger the flasher. The flasher gets triggered by the circuit going through the filament to ground, but that being the case where is the pulsed 12 V coming back into the circuit? I know when I pull the Hazard Flasher on the B\L wire at the flasher drops to a low voltage 2-3 volts. The G\Y and G\B wires out of the hazard switch also carry the same low voltage while the G\W direct from the flasher pulses 12 V, so how is 12 getting pulsed to the lights???? I must be missing something fundamental here, but these are the voltage readings I am getting and my meter doesn't lie. Argh!!

Your 76 has the exact same turn signal switch as mine. The red wire harness is for the headlights and I don't have any issues there.

I guess another good question to ask is if I only had the turn signal switch, the flasher, a 12 V battery and a left and right turn signal out side of the truck, how would I wire that to work??

 

[capperdog]

I just looked at the associated 6-pole connector in the truck harness and it does, as you mentioned earlier, have only four wires. It has GB for left turn, G for power (mates with GL of the switch), GY for right turn, and GY (yes, GY) for the horn. Toyota did some funny stuff over the years. I don't know what they were thinking here, but it looks like they didn't actually use the rear turn signal wires that are attached to the switch. Huh.

Anyway, see if you can light the right and left turn signal bulbs just by applying 12v to the associated GY or GB wires at the harness plug (and ground to the frame or body, of course). That'll rule out any issues from the column connectors to the lights. If they light up OK, then you can look at the switch further.

Kewl... Now we know exactly what the extra wires are! Thanks for that! I did hook 12 V directly to the wires at the connector and the turn signal both left and right do light.

 

[capperdog]

Thought I had found an issue. I had lost 12 V at the flasher and switch with the key on. Problem was at the fuse block. I need to clean that up to stop any other headaches from popping up.

In the meantime I seem to have everything wired accordingly. Only the GY, GB and GL attach to the signal switch. 12 V shows on BL and is switched between left and right.... easy, but in my case as soon as that 12 V on BL attaches to a load it drops to 0 V immediately and the flasher does not engage.... Just don't get it. Even taking the signal switch out of the picture and connecting GL directly to GY or GB same case. Connect 12 V from another source to GB or GY and turn signal lights....

Any ideas??

 

[spotcruiser]

There must be some issue with the flasher. I've never had to replace the flasher on a LC, but standard flashers are just thermal devices. When you turn on a light, current flows through the bi-metal contacts in the flasher, the bi-metal contacts heat up and open, the contacts then cool down due to the open circuit, and the process starts again. That's why loss of one bulb in a turn signal circuit will often light the remaining lamp but not flash; there isn't enough current with a single lamp to cause opeing of the bi-metal contacts.

Modern electronic flashers have small timing circuits to time the opening and closing of the lamp circuit, so they're flashing is not dependent on load.

I think I just figured out your issue. The flasher must be worn out. I'm thinking you must be seeing voltage when you have an open circuit, but the contacts in the flasher are so poor that you see nothing with a load connected. It's similar to seeing proper open-circuit voltage at a battery cable with a poor conntection, but being unable to crank the starter when you try to draw current across that corroded connection. Try a new flasher.

BTW, sorry that I took so long to get back to this. I stopped for dinner.

 

[capperdog]

No problem on the reply and ideas boiling down to a worn out flasher. Problem is the flasher is brand new and works perfectly with the Hazard switch.

Can you explain why/how when the hazard flasher is engaged the voltage on GL at the Hazard is 2-3 volts, so are the GB and GY going out that are flashing. The actual pulsating voltage is on GW from the flasher. I see flashing and know it is full voltage, but my meter is telling me different. Is there something fundamental here I am missing?

 

[spotcruiser]

Crap! I didn't see or didn't remember that the flasher was new. I was thinking that just the turn switch was new. Stock flasher?

Well, it may be the same issue I mentioned with the battery scenario. I can't explain the 2-3 volts at GL unless you have a high resistance connection somewhere upstream of GL (in the flasher, hazard switch, or associated wiring).

I just looked at the flasher on the '76 that I'm working on and it just has two wires (GW and GL, per the diagram). That means there is another connection somewhere; either at the Hazard Switch or at one of the crappy in-harness node connections that Toyota does. I think I'd look at resistance in that GL circuit from the turn signal switch to the flasher.

I'll give it more thought. Good luck.

No problem on the reply and ideas boiling down to a worn out flasher. Problem is the flasher is brand new and works perfectly with the Hazard switch.

Can you explain why/how when the hazard flasher is engaged the voltage on GL at the Hazard is 2-3 volts, so are the GB and GY going out that are flashing. The actual pulsating voltage is on GW from the flasher. I see flashing and know it is full voltage, but my meter is telling me different. Is there something fundamental here I am missing?

 

[capperdog]

Great thanks! At least I know at this point it all is connected correctly and what all of the wires are. That was a big mystery and messin with my mind! I will check the resistance from GL back to GL at the flasher. I am also going to clean up and re-install all new fuses at the block. That voltage shifting issue was blowing my mind as well until I figured that out. That very well may be the issue itself.... Dunno but needs to be done anyway....

Hey thanks for your help and let me know if you have any other ideas. I may not get back on this until next weekend, but will keep you posted.

Cheers!
Steve

 

[spotcruiser]

Here's a thought. Replace your "Turn" fuse and/or check your connections at the fuse block for that circuit (front and back).

Looking at the function of the GR wire at the Hazard Switch, it feeds power from the stop light fuse to the Hazard Switch/flasher/lights only when the Hazard Switch is "on". When the Hazard Switch is "off", the power for the lights comes from the Turn fuse. I have seen fuses where the elements are imperceptably cracked, such that they have continuity and look good, but will not supply sufficient current to do work. You'd think they'd burn up, but there really isn't enough current passing through them to burn them up. Or, perhaps you have poor connections at the fuse holder for that fuse.

Just a thought.

 

[Coolerman]

The GW wire with the bullet connector mentioned above is a left over from the 74 and older wiring which had the brake light signal going through the turn signal switch due to the older trucks using one bulb to do two things (Brake/Turn). When Toyota separated the turn signal to it's own bulb, that connection to the brake switch was no longer needed. Interestingly, the FJ45's that had the separate turn bulb has the GW wire wired BOTH ways. This means you can use either style of rear lights, a single round light like the early Cruisers or the split turn/brake light.

For those wanting to see every schematic I have been able to find for the FJ40/45's including the Haynes schematics go here: http://www.globalsoftware-inc.com/coolerman/fj40/schematics/

I have found the 76/77 harnesses to be the most "variable" meaning they can deviate from the schematic especially with wire color in the turn/hazard circuit.

 

[capperdog]

Here's a thought. Replace your "Turn" fuse and/or check your connections at the fuse block for that circuit (front and back).

Looking at the function of the GR wire at the Hazard Switch, it feeds power from the stop light fuse to the Hazard Switch/flasher/lights only when the Hazard Switch is "on". When the Hazard Switch is "off", the power for the lights comes from the Turn fuse. I have seen fuses where the elements are imperceptably cracked, such that they have continuity and look good, but will not supply sufficient current to do work. You'd think they'd burn up, but there really isn't enough current passing through them to burn them up. Or, perhaps you have poor connections at the fuse holder for that fuse.

Just a thought.

Sounds like you're on to something here. I plan to clean the fuse block and replace all of the fuses next weekend. I agree that it may have voltage but cannot carry the current necessary due to bad connection, faulty fuse etc. I was getting varying voltages as well, so the fuse block is the next stop. Will post up what i find next weekend. I already pulled the 40 out of the garage... Sorry FJ but my 2012 Titan get seniority over the covered parking! Will keep you posted.

Thanks again for all of your help!

 

[capperdog]

Thanks for the heads up and schematics.... Badly needed!

 

[subzali]

I'm still following this thread, and I actually found my problem though I haven't updated this thread yet. I'm waiting to actually fix the problem before I do that. It was a weird one.

For you though it may be as simple as cleaning the fuse block and putting new fuses in. The electrical system can do some wonky inexplicable things until that's all cleaned up nice.

And you'll chase your tail trying to find it until the fuse block is clean. Good luck

Sent from my iPhone using IH8MUD at 85mph in an FJ40

 

[capperdog]

Cleaned up the fuse block and replaced all fuses. I now have stop, tail, turn, running lights and headlights high and low beam.... And nice even voltage readings wherever I check!

Thanks for the help gents! Now I have to figure out the wiper setup and see if the motor is any good. Any hints on how to service the internals of the wiper system?? It's a puzzle to me. I don't see how to get inside to service the wipers.

Anyway I will search the site later today for info, but if anyone has a link please send it.

Just wanted to report the fuse block cleaning did the trick and I am one step closer to a safety inspection!

 

[cuencanolenny]

Turn signal & Hazard wiring

I found this thread very interesting as I am installing a new American AutoWire (AAW) Hwy 15 harness in my 1970 FJ40. My wiring harness was a mess and consisted of color code red and black, black and black, and an occasional blue wire. I popped the $100 for a new turn signal switch. The AAW instructions are based on a person using a GM or similar steering column. Consequently when I get to the loose ends of the wires it is up to me to figure out what to do. The FSM diagram (I bought the laminated, color, version on the net) looks pretty busy. I suspect part of that is the limitation on the size of the fuse panel vs the 15 circuit unit I now have installed. So here goes;

On the FSM diagram, power to the turn signal switch (TSW) is G via the Turn Signal Flasher which is fed from the fuse panel. There is a junction to the VR shown. The power to the Stop Light Switch (SLS) is a junction off the headlight switch to fuse panel. Power to the Hazard Switch is via an inline fuse off a junction to the alternator/ammeter wire.

I can take power to the TSW from the Purple Turn Switch at the Hwy 15 Fuse Panel (#7). I can take power to the SLS from the Orange wire at #9 on the Fuse Panel. It is easy enough to "Y" off of the GO & GY wires to go to the turn signals and stop lights, however, I'm confused regarding the Hazard Switch. The FSM shows a second flasher, my fuse panel defines the flasher as being for turn signal and flasher. Also there is a turn relay on the fuse panel. Operating from the water hose philosophy, if the hazard switch is "Off" there is no water passing through to it. So I should have turn signals and brake lights. But the FSM diagram looks very busy at the Hazard Switch with GY & GO (2 ea) feeding into the switch which shows seven connections. That looks very busy for what should be a DTSP switch. I am thinking that I can combine the GY wires and the GO wires at the hazard and then continue to the front and rear harnesses for turn at the front and turn stop at the back.

Does anyone see an issue with what I am proposing? Do I need to add a flasher for the Hazard Switch? Do I need to find a Hazard Switch with 7 connections? Thanks.

 

[cuencanolenny]

Turn Signal & Hazard wiring

Rudi suggested that Coolerman and Pin Head address issues like this and so I PM'd them requesting they review this thread. I had found these links for wiring turn signals and hazards into a hot rod and that is why I thought the Toyota diagram looked a little busy. Since I am running trailer lights in my new bumper which combine stop and turn, do I need one of these converters as well? I wonder how long that will take to get down here to me if I do. Thanks for looking, I could use the help and confirmation so I can proceed.
P.S. I'm also attaching a picture of the new battery and ground cables I received yesterday from CEAutoElectric Supply in Chandler, AZ. Very high quality.

 

[Pin_Head]

Cruisers '74 and earlier have very different wiring in the turn signals and brake lights than in the '75 and later cruisers that are the topic of this thread, so it would be better to start a new thread.

On early cruisers, the front and rear turn signals are separate circuits at the turn signal switch and the rear turn signals do double duty as stop lights. On later cruisers the L and R turn signals are the same for front and rear and the stop light is separate. These are very incompatible circuits.

The advantage of using a GM wiring harness is that GM used the same type of wiring as early cruisers and if you use a GM steering column, the harness is plug compatible for both the turn signals and other GM switches. If you are using the Toyota column and switches, there is no advantage over just using new bulk wire. You have to recreate the new harness one wire at a time using the old harness as a template and reusing the original plugs. It is a lot of work, but if you label all the connectors and do one wire at a time you will get it done. It is easier to do it with the harness out of the truck and on a table.

 

[cuencanolenny]

Thanks Pin Head, I have created the new thread here https://forum.ih8mud.com/40-55-series-tech/790694-rewiring-1970-fj40-scratch.html#post9001153, how would I go about deleting my stuff from this one?

The old wiring harness is not Toyota. Several times I have re-visited it to see if peeling back some of the forever gummy tape would reveal the original harness. Nope, there is only red/black, black/black and an occasional blue wire. There are no soldered joints, all twisted wire wrapped in tape. It is just a mess, so much so that it was pointless to try and repair and I had already fried gauges in a replacement instrument panel so I want a more trouble free setup.

 

[Pin_Head]

I would presume that your harness closely approximates the OEM Toyota one if it uses all the original fuses, switches, devices and plugs. Usually any changes are to either add something new or repair a burned out circuit. You should still be able to recreate the proper harness by looking at the one that is working now and by looking at the wiring diagram. The hard thing is if the wires at the plug are not properly identified by color code. If this is the case, you will either have to find the other end or the wire or have to use an ohm meter to figure out the plug position connections. There is no easy way to do this using the Toyota parts. The reason people use a GM harness is because you can get a GM steering column for cheap and it is plug compatible for the turn signals, hazards and some even the headlights.

 

[cuencanolenny]

The pushbutton for the horn might be original, but that is all. The turn signal unit was pretty worn out. I could have it stay on if I loosened the clamp by the steering wheel and rotated it one direction or the other but it wouldn't stay blinking if I let go the lever on the other direction. I'm not sure what is involved in converting to a GM steering column but finding one down here would be difficult to say the least. I will just have to try and replicate the diagram as best I can with what I have.

Are the sources of power that I identified acceptable? I can't imagine that it is important to tap into the VR return line, stuff like that. Power is power, yes?

 

[Pin_Head]

There are two types of power you need to be concerned with:
Constant power that comes off the chassis side of the amp meter where the alternator wire and ignition switch wires attach and key on power which comes off the switched side of the ignition switch. Wires from these locations feed the two bus bars of the fuse block. HTH.