I have a 2004 chevy monte carlo. I am trying to move my climate controls into my glove box. So i have all the wires hooked up, i just extended all the wires and connected them back. Now when everything is hooked up, i start the car to see if they will work and they will not work and my interior lights wont come on either. Also my service engine light is on too? Does anyone know why this is.

 

If the HVAC wires are the only thing you messed with, I'd recheck them, make sure you did not cross anything when you spliced them (sounds like a short somewhere). what happens if you leave the HVAC panel disconnected? Do the lights work?

 

Make sure each is extended, don't take shortcuts like combining negatives (some negatives are NOT necessarily ground wires). Interior lights on some cars have independent negatives for dimming.