Please help!

I have a 2001 buick regal that’s AC sysyem seems to be possessed. It started with a burnt headlight switch. All glow lights and larger dash lights went out. Then the AC started just changing for no reason. Shitting on and off or changing temp by itself. We replaced a relay and it worked great !!! Right up until the interior lights were suppose to kick on at dusk Of course the lights didn’t since we hadn’t replaced the switch and harness yet…We’ve replaced the switch and harness and a fuse and nothing happened on the AC so we replaced a relay. Still nothing. I could suffer with AC for a while but it’s stuck on 90 heat and high blower. Please help. Any input would be welcomed. Thanks, Mary

I hate to say it, but this sounds like a problem that requires a dealer shop to figure out. I’m guessing you’ve got a bad ground in the dash somewhere, but that’s a guess.