turn signal problems

ok im having this crazy turn signal problem. it works on the drivers side(all lights). the rear passenger side lights dont do anything under any circumstances. the passenger front turn signal light just lights up, no flashing.
when I use the hazards, everything the front passenger side starts flashing. the rear passenger does nothing.
I cleaned the ground going to the right passenger side light assembley but it didnt work. all the bulbs look new and dont look burnt. all the connections appear to be hooked up. all fuses are good.
the only thing i can think is that somewhere in the wiring going to that light assembly is bad, causing the flasher not to work for right hand signaling. that sound right? what else should i be looking for? should i just probe wires till i find one that doesnt have 12v? I have a wiring diagram to go off of but im a newby when it comes to wiring. how would i test these wires? probe through the wire and put the other lead on a good ground? hellllp!!!

get a piece of wire strip the two ends touch it to the side of th bulb and ground it to a part of the truck if the light works then you have a ground short.

i had this same prob when I first got my cucv, turned out that one of the contacts in side of the bulb mount was corroded, and cracked. I replaced the bulb socket that I bought from autozone for a couple bucks, and now everything works great.

I had a bad ground on my front driver side turn signal( inside the socket, the metal tab that makes contact with the side of the bulb-Ground- was missing)

check to see if your ground wire is still attached to the grounding port, it is located on the driver side wall just up under the dash, it could be breaking loose or came off all together

Ground(s)

For the turn signals to work (flash), both the front and rear bulbs must be working. Without both bulbs then the flasher can't draw enough current to heat up and cycle.

The wiring for the tails lights is:

light green: backup lights
dark green: right turn signal
yellow: left turn signal
brown: stop
black: ground

From your description, the circuit for the right (passenger) rear has a break in it. Either the dark green wire or the ground is bad.

Start by turning on the flashers and then remove the turn signal bulb and checking for voltage at the green wire. (the diagram is showing yellow, but I think it is a typo. I haven't physically checked it). If no voltage, then trace the dark green wire back to the tee connector by the pintle hitch. Also check the ground from the bulb socket to chassis ground.


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Warthog said:

For the turn signals to work (flash), both the front and rear bulbs must be working. Without both bulbs then the flasher can't draw enough current to heat up and cycle.

The wiring for the tails lights is:

light green: backup lights
dark green: right turn signal
yellow: left turn signal
brown: stop
black: ground

From your description, the circuit for the right (passenger) rear has a break in it. Either the dark green wire or the ground is bad.

Start by turning on the flashers and then remove the turn signal bulb and checking for voltage at the green wire. (the diagram is showing yellow, but I think it is a typo. I haven't physically checked it). If no voltage, then trace the dark green wire back to the tee connector by the pintle hitch. Also check the ground from the bulb socket to chassis ground.


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warthog, i believe that all the sockets are working. when i turn the lights on without the red lenses in place, i can see that the lights come on. i know the bulbs are good because i swapped them from the known good side. im getting no voltage to that green wire, i even checked it closer up front, under the truck, by the exhast and frame, nothing. I moved up to the steering column harness connector to the switch. the known good side gave me three different wires that flash 12v, only when drivers(good side) is aplied. when checking the passenger side signal, only one wire gave me a steady 12v when the switch was applied. does this sound like the switch to you? the only thing that makes me wonder about the switch is, the front passenger side lights up steady so woulnt the switch be doing its job?

1)If you turn on your hazzards do all light blink like they should?

2)And what about brake lights do you have those?

3)When you use your turn signal both left and right just lights up but does not flash?

ok i got them working for now. to answer your question dstang97, yes the flashers were working on everywhere except the rear passenger side. the problem ended up being the wiring harness that connects all the lighting to the firewall and on into the cab. i took it apart and the green wire was pulled out a little bit so the metal tab wasn't contacting the rest of the harness. its great that i got it figured out but it wasnt a day before all the turn signals and stop lamps and hazards stopped working. i started a new thread called turn signal amps i think. im wondering if the right fuze was installed now cause everything looks good but nothings working.

ok, so after days of searching the forums and chasing wires and connections I still havnt got any progress. my break light fuse blows the instant you press the brake. the passenger rear everything doesnt work unless you turn the lights on for some reason. the drivers side rear has a lit up backup light going along with the turn signal. hopefully one of you guys is an electrical genius, cause im obviously not. or maybe someone has had a very similar problem?
this is what i changed out......both rear turn signal sockets. didnt help anything.
fixed the wire at the fuze box. i changed all the fuses.
heres the symptoms

left hand blinker
blinks slowly(intermittent).

left hand blinker with lights on
both filaments blink. back up lights illuminate when they shoulnt.

right hand blinker
no power to any bulbs

right hand blinker with lights on
one filament blinks. brown wire definitly controls that one

all lights cut off
i know this is the circuit breaker device siting in my #7 fuse port. its gets very hot when you leave the lights and signals on. i tried putting a 30 amp fuse in as the diagram shows but it doesnt last very long before blowing.

-i also know that the green wire i talked about that goes into the firewall harness to the fuse block has something to do with the right signal. when i pulled it out and put on the turn signals, it just lit up steady with no blinking. the front blinked fine.

I have gone over every piece of wiring that i could find. i just want my brake lights to work. i think the two systems are related somehow and screwing each other up but i cant find where! I need this thing on the road yesterday. anyone have any suggestions? also Im going to try to attach a rough wiring diagram for the brake lights. Im wondering if it could be in the turn signal switch because i know that one of the brake light wires goes through there. Maybe it could be in the blackout switch? is that possible?

sorry i cant attach the diagram. for the brake lights i think it goes like this; from what i can tell. from the brake switch to the fuse box. then it goes to the blackout switch. i think from there is goes to the turn signal switch and i think on to the brake lights. sound right?

If you took the firewall/fuse box connections apart, there may be more connectors pushed out and/or some wires touching. Take it apart again and clean everything. Use some di-lectric grease on the contacts when you put it together again.

Remember that these trucks are 25+ years old and things break, corrode, give out.

You could take it to the shop and pay $75+ an hour for them to troubleshoot it. But where's the fun in that.

the dielectric grease is just to prevent corrosion right? also I already checked everything else. no corrosion and nothing out of place. I think I may need to rebuild part of the harness that goes to the fuse block. the wire has been pulled on so much that it has lost all that rtv looking stuff that holds the wire in. i think ill just use rtv.

ok so i replaced the turn signal switch and it didnt help at all. im kind of out of things to check now. i have fixed the wiring harness, changed two sockets, gone over all wiring that i can reach, changed the bulbs.
the only thing that i havnt completley ripped out is the trailer wire connections. im assuming that is what it comes with from the factory. i would like to just rip it out and start from scratch but the wiring doesnt really make sense to me. it doesnt seem to be pigtailed(paralell). anyone have any experience with this?

Hate to tell you this after what you have done so far, but you may have to start again from the beginning. You may have to get out the volt meter and go through and check the harness (power and grounds) to each socket. I had this same problem with mine. I didn't have to replace the switch though. It's going to be something simple and can be easily over looked. I spent the better part of a week figuring it out. What I found was this. I found this in the front right turn signal socket. I found this when I was troubleshooting. I noticed that when I moved the socket and contact was made through the bulb, everything worked. I missed this the first time going through. Another good thing to do is read up on the wiring schematics. Just follow the pathways. Like Warthog said these are 25+ yrs old. Be careful with harness. Best not to pull apart the trailer connection, but probe and test it with the volt meter. Again like Warthog has said, the fun of it is when you figure it out. And of course we are here to help. Keep us updated!!!

taildragger03 said:

What I found was this. I found this in the front right turn signal socket. I found this when I was troubleshooting. I noticed that when I moved the socket and contact was made through the bulb, everything worked.

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These contacts cause a lot of issues and are often difficult to spot. The contacts lose their tension and corrode over time. It's not a bad idea to replace the suspect sockets, and of course always use dielectric grease to prevent future corrosion.