Hey guys i got a '91 s10 blazer 4x4... i am having a heater blower problem... i know the blower/fan works but when i go from low to high it doesn't turn on... While i am driving it will randomly turn on... It's very frustrating! What else controls the heater fan/blower to turn on? Any advice is much appreciated... if you got pics that will help me a lot as well... Thanks in advance guys!
The problem you are experiencing sounds like a worn out blower motor. Next time it doesn't work, test for power & ground to the blower motor when on the HIGH setting. If you have power and ground and the blower motor still isn't moving, it needs to be replaced.