Have searched extensively- still need help, plz, re:dipped beam & brake light

[reyxlp]

I'll try and make a very long story as short as possible. I'm three mechanics in and still haven't solved it yet. I've searched extensively and come across many similar issues but not the same combo of issues I'm having.

 

2006 CTS w/110,000 miles, no major issues before this.

 

I'll start with this: is there any related wiring, control modules, fuses, etc/whatever, between the headlamps and the rear upper center brake light? Also possible the driver side horn, which also isn't working? All these things seemed to start failing around the same time.

 

I'm getting the dipped beam warning on the driver headlamp and the brake light warning for the center upper rear brake light. They always seem to happen around the same time.

 

Mechanics have ruled out bulbs and plug/outlet contacts, those seem to be fine. New battery and alternator is good- both tested and no issues.

 

I replaced both headlamp mount trays with new ones myself, that stopped the headlamps from coming loose over bumps or potholes. That used to happen and I thought that was the only reason I would get dipped beam errors. I would go over a bump, I'd get the dipped beam warning, one or both headlamps would stop working and sometimes I could get them working again just by turning the headlight switch off and back on, but usually I would have to stop, get out of the car and physically push them back into place, and then they'd work again. Now, only the driver side headlamp will stop working but no correlation to rough road or bumps, and pushing it back in doesn't fix the problem, only turning the lights off and back on again will do it.

 

Anyone have any experience with this combination of issues?

 

Really appreciate any help..

 

Thanks!