Alright guys, I'm completely stumped. I installed a new radio in my 2009 tc, used wiring harnesses to get everything connected. After everything was hooked up the HVAC center screen would light up when the dash cluster was off, then when I turn the dash lights+headlights on the HVAC lights all go out. I tried troubleshooting it by taking out the circuit board, tried the t302 re-solder thing, nothing changed, then I noticed the voltage regulator on the back of the board became extremely hot and now NOTHING works. I have no control over the a/c system and the screen doesn't even display anything or light up.

I have searched hours everywhere already and can't find any answers.

What the heck am I doing wrong??

 

Well your hvac has a certain brightness with headlights on. Another brightness when headlights are on. I THINK. Haven't been in my car since November .

Sounds like something shorted out but I don't know how unless somehow you plugged the wrong plugs into the harness. Don't even think they match up though

Maybe coincidence and your regulator went bad? Got a friend with a TC that you can swap hvac stuff to try to see if issue is in wires?

 

Sounds to me like you installed a aftermarket radio with a harness? You might have hooked up something wrong to the new radio and it's feeding voltage back to the illumination circuit.