1990 Chevy Shortbed Electrical light problem

[Jayhawk]

Hi there,

Hope someone can steer me the right way.

All lights in the back are not working.

here is what i have done

1. Replaced all lights in the tail lights.
2. Replaced the neutral/safety switch
3. Replaced the other switch right by it connected to the the brake pedal.
4. Replaced the circut boards on the lights.

Before I did #4 only the drivers taillight was on with the ignition off. If I moved the turn signal doen, the light went off.

There are no brake lights when you push on he pedal.

Has no trailer harness.

With the truck off. The rear lights are on. I disconnected the plag at the rear of the truck. There is power coming from the front of the truck on the yellow and one of the green wires.

Any suggestion on where to go from here?

[leolkfrm]

welcome to the forum
I would keep tracing forward and look for a bad spot in the harness, maybe its rubbing

[silverhairdeere]

the same that was wrong with mine . mis adjusted brake switch , drove me crazy trying to figurer it out .

silver hair deere

dead battery thing ?

[Jayhawk]

Originally Posted by leolkfrm

welcome to the forum
I would keep tracing forward and look for a bad spot in the harness, maybe its rubbing

How would that explain the two wires having power to them? I bought a turn indicator switch today. Soon as the rental steering wheel puller comes in, I will change that out.

On the wiring diagram, those two colored wires go to the the rear lights.

Thanks for the tips. I will psot as soon as I change them out and se what the results are.

Thanks

Ron

[bradrhale]

if you have power back there, i would check continuity on the ground side.

[Jayhawk]

Originally Posted by bradrhale

if you have power back there, i would check continuity on the ground side.

explain that process if you don't mind. I kind of know what you are talking about.

thanks

[bradrhale]

you have a ground wire that comes from the lights and heads back up front through that plug. take a multimeter and trace the ground wire down to see if it has seperated. that would indeed cause your lights to not work. start with the plug and go backwards towards the lights. yank the bulb and test for continuity there. if that checks out, go on the opposite side of the plug and work your way back to the front of the truck.

[silverhairdeere]

before you tear everthing out , please try reajusting your brake pedal switch .

silver hair deere

[silverhairdeere]

any update ?

silver hair deere

[Jayhawk]

Here is an update.

Replaced:

1. Replaced all lights in the tail lights.
2. Replaced the neutral/safety switch
3. Replaced the other switch right by it connected to the the brake pedal.
4. Replaced the circut boards on the lights.
5. Replace turn signal switch.
6. Replace turn signal flasher

Adjusted the thing you showed in the picture. Tail lights are off now.

Everything works fine with the headlights off. All brake and turn signals

When I turn the headlights on, one tail light does not work (drivers). When I turn the the right turn signal on the reverse light flashes on left side and the reverse light and the light above the reverse light on passenger side alternate flashing.

So what now? I think I will go though all the bulbs again to make sure they all work and are the correct ones.