2009 electrical problems!!!!

[TexasPM]

2009 CC Lariat, few days ago dash lights went dim like I had hit the headlight switch. Then today I was driving and the ac blower was speeding up and slowing down continuously. The the dash light thing happened again. I've heard the guinea pig blend door noise for a while, but this sounded like the actual blowers motor speeding up and slowing down? Anybody have any ideas? Thanks, kp

 

[91turbogsx]

I'd check for voltage fluctuations or low voltage. Maybe your alternator is taking a dump or bad connection/ground somewhere.

 

[TexasPM]

Not voltage fluctuations. Alternator is charging fine. The dash lights aren't dimming they are switching over to night mode, which leads me to believe its computer something? But is it related to the ac or just coincidence?

 

[91turbogsx]

Do you leave the headlight switch on auto? Also does it also have climate control?

 

[Gary]

Sound like a body control module problem. With a good scanner you can "get in" the BCM and turn those things on and off and change fan speed, then you will know if its the wiring or BCM. Also I'd check for TSB's for your problem.