# Brake light and blinker electric problem



## jtwoods4 (Dec 22, 2011)

Needs ome help from a wiring expert. My 1969 gto brake lights and blinkers work fine when the headlights are off. When I turn the headlights on my driver side brake light and driver side blinker will not work.

Any ideas?

Sent from my HTC Vision using AutoGuide.Com Free App


----------



## Cavtrp (May 29, 2012)

Usually caused by a short in the wiring somewhere a long that side. Check for some spot it is bare to ground out.

Sent from my SGH-T589 using AutoGuide.Com Free App


----------



## jtwoods4 (Dec 22, 2011)

I just looked at the wiring diagram and it appears that each side of the tail lights plugs into its own connector in the steering column. Maybe the connection for the drivers side is lose. But that wouldn't explain how they work when the lighs are off.


----------



## jtwoods4 (Dec 22, 2011)

I just replaced the flasher relay located under the drivers side dash. Did not fix problem. I am not sure what to test from here.

Scenario:
All lights work as long as the headlights are turned OFF. When I turn the headlights on I lose my driver side rear blinker and brake light.

Anyone have a suggestion of how to test? Or what to test?


----------



## 646904GTO (Feb 10, 2008)

You have a bad headlight ground or blinker assembly ground. Test by putting a test wire with alligator clips on the ground of the headlight to engine ground.If all works trace the wire back to where it screws onto the core support.


----------



## jtwoods4 (Dec 22, 2011)

Correct me if I wrong but the blinker asembly grounds are where the lightbulb housing touches the frame. Not sure where the headlight grounds are.... Can you explain?


----------



## BearGFR (Aug 25, 2008)

As I recall, there's a separate wire in the sub-harness that goes to the headlights that's a ground wire. You can recognize it because it'll be a single wire with a round terminal on it (to put the mounting screw through). It (they - there might be one on both sides, I don't remember for sure) connects to the core support. Make sure you've also got the ground strap in place that goes between one of the inner fenders and the frame. That strap is the ground path for the core support when the inner fender is bolted to it. It doesn't ground so well through those rubber bushings that secure it to the frame 

Bear


----------

