So my 2003 Impala has a problem with the a/c blower. My car has around 180K miles and has been relatively good. The a/c blower was hit and miss for a while but then worked consistently until recently when it has decided not to work at all. I have read previous threads about changing the blower motor (didn't fix problem), blower relay (didn't fix problem). When the fan problem was hit and miss I bought the a/c control switch at a junk yard and that did not fix the hit and miss problem. I also replaced the head light switch thinking that was connected somehow. For good measure I also tried the fan relays by the fuse box.
Anybody else have this problem? How did you or your mechanic fix it? Besides buying a new car...

 

Welcome to the forum

Here is a blower schematic, I would start with checking all connections, check for melted or loose connections... be sure to inspect each pin in the connector for tight fit and that it is fully seated in the connector....
I'd start at the blower, then the control switch....

 

Ends up it was the ignition switch. This is at least the 2nd time the switch has been replaced. Just had one put in 18 months ago. Oh well. Problem solved.