Brake light issues

[lukbrw]

First started off with the right rear turn signal not working.....turned out the complete socket was shot. So I replaced that.

Now with the head lights off, blinkers work and brakes work.

With the head lights on.....blinkers work but the brake lights do not come on. Any ideas? The wiring is not stock. So if there is a way to at least start to figure out how to connect it.

[Toops]

Try replacing the headlight switch. They tend to wear out and short out the tailights when the headlights are on.

[old Rusty C10]

make sure that there is no short in the harness between the brake light switch and headlights.. ive seen this on a truck with rot

[Keith Seymore]

I can't quite tell from your avatar picture: Is it a stepside?

If so, it could be a ground issue.

On my '80 stepper, I used to take the taillight brackets off every spring and repaint them and reinstall with new stainless fasteners. It came with little star washers on the taillight brackets, which were supposed to cut into the paint (which they did) and provide the ground, but since they would get all rusty I would repaint and replace tem. Eventually I had no turn signals and no brakelights.

When I finally figured out what was going on I added a separate ground wire from the light socket down to the frame rail. Problem solved!

K

[silvereagle07]

Get a test light, ground it , test both sides of the rear stop lamp with the brake pressed. If the test light lights up on both terminals you have a ground problem.

[lukbrw]

yep, it's a step side and the tail lights are out of a gremlin. So completely a home wire job...which was why I'm trying to figure out what goes where. The color of the wires are what ever the previous owner had, so nothing I can compare to stock.

I replaced one socket, the original one was metal and the new one is plastic. So I may need to ground it??? There were two wires going to it, so how do I know what one to ground.

I'll start with the test light also to see if both of the contacts light up like you said. Just wierd when everything works except at with the headlights on.

[Keith Seymore]

Grounding issues can definitely result in weird behavior.

I clamped the bare end of the ground wire to the (metal) taillamp socket, and then ran the other end to a good clean bare spot on the frame.

You may have to do something a bit more tricky if your socket is plastic.

K