2004 Chevy Express 3500
I bought this van about a year ago for work. It was well cared for by a grains company and in great condition. My issues started a few days ago. First I noticed the rear ac/heater stopped working. ( It has worked since I bought the van ) I also noticed when I put the rear ac/heater **** on high it would turn on both my interior lights. Tonight the issue has spread. When I step on the brakes my driver's side brake light will light for a second then dim out to nothing, the reverse lights turn on and stay on until I let off the brake. At the same time both interior lights turn on. Also when I turn on a blinker, the interior lights flash with it making it look like I'm having a rave party in my cab at night. This all only happens when my headlights are on. If the headlights are off, the brake and reverse lights, light up brightly, together when I press the brakes. Along with the interior lights. Prior to these issues my headlights flickered and turned off. I think my headlight switch is going bad as I can wiggle it and make the headlights turn off and on. Could a bad headlight switch cause all of the problems or do I have gremlins in my van ? Any advice is appreciated and I am thankful for.

 

So turns out the ground wire at the rear pass brake light somehow magically snapped off. It's all better now