Im having a problem with my AC in my 85 chevy blazer, a few nights ago it was working fine and the next day i woke up and got into the car to go out the AC blower wouldn't turn on at all, I hooked up the blower to the battery and it works fine, I just tested it with a test light and having the test light hooked to ground both of the cables on the blower had power going to them, Im wondering if there's a short some where, If anybody knows whats going on let me know, Also where is the AC relay for the blower, Ive checked one of the ones under the hood and nothing.

 

Your blower motor resistor has gone south. When they go, they either run on high only or don't run at all. They are usually either in the duct work or in the blower motor housing.

 

I just changed the blower motor resistor and still nothin, I checked the purple and black cable that come from the AC blower and both are at almost 14 volts, I dont think they are suppost to have power to both of them, When i hook up the blower to the battery it works fine, But the 2 cables on the blower are both getting power.

 

Anybody know what could cause this???