[Mudhucker]

In my truck my turn signals work fine when the headlights are off, but whenever i turn them on the signals stop working?? Man i Hate wiring, also my left rear tail light isn't flashing or my brake light, but the running light works fine?? Help on this would be great, thanks

 

[Toynut]

sounds like a short (one of the wires from the headlight circuit touching one from the signal lights)
do you have a test light ?
and a wiring diagram for your vehicle ?

 

[Woke Up Dead]

It sounds like a ground problem, I had a similar dilemma on my Samurai. Under the back of my truck, right next to the bumper there were two groups of ground wires (one for each of the rear lights) attached to two screws that threaded up into the bottom of the truck. The problem in my case was that one of the screws, and the ends of the wires attached to it, were so dirty and rusty that they did not conduct electricity anymore, resulting in a whole bunch of weird things going on (brake lights blinking, reverse lights turning only half-way, things would work fine with headlights off but would malfunction when I turned them on or touched the brakes, etc.) I simply cut the ends of those wires, extended them all to the other screw and grounded them there, it solved everything.

I would say this is more likely than what Toynut is suggesting, since a short between two wires would mean that the rubber coating around BOTH wires would have had to rub off in the same place. Possible, but unlikely, and a hell of a lot harder to find, so look for grounding problems first.

 

[Mudhucker]

Perfect the problem sounds fixable with minimal efforts, and i have a computer program at work called alldata that should have all the diagrams i need. I think the bad grounds sound very good as this all started after i got stuck pulling my friends truck out of an alkali pond:mullet :******* Stupid mud bogging?? where's the challenge in alkali?? it's not mud it's like trying to 4x4 in a giant bowl of pudding that smells and eats at your truck apart.

 

[Longman]

Do you have a body lift? If you do re-do the the ground for the lights to the frame. The ground should be located behind one of your taillights.