Trailer lights? {Fixed}

[BuzzStPoint]

95 Chevy pickup.
It has the T harness in back. I noticed last night that all the lights seem to work fine until I turn the headlights on. Last year I replaced the T harness to allow a trailer wire.

When I turn the head lights on, they go bright and when I push the brake, the lights go out on the trailer. Signals work fine. Turn the head lights off and the trailer lights work normally.

Any ideas on what could be wrong? I have a 4 pin harness.

 

[Mr_Shamrock]

Re: Trailer lights?

Re: Trailer lights?

Check your ground. A weak ground can cause all sorts of strange combinations.

 

[BuzzStPoint]

Re: Trailer lights?

Re: Trailer lights?

Total ground issue.

Had my brother look at the lights with me tonight.

I made some trailer guides extending up the boat to help me load the boat. Not too long ago I moved the light from underneigh the trailer to the tops of the post... Didn't think of it at all. PVC pipe for the guides. Lights were grounded to the trailer. Moved the lights, ungrounded them.

We ran a test ground and they worked. I just need to run a ground down the pvc pipe to the trailer..