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!

Aztec

 

By any chance was it cold outside? This started happening to me as-well only difference is my wont work at all until i get moving.

 

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.

 

ddaw735 it was not cold outside...

i dont think i need a new blower motor... it turns on randomly while i have it on low, med or high... What else would control the low, med, or high and where is the part located?

 

Guess you aren't interested in diagnosing the problem...

 

i see what you meant by checking the motor... Looks like i need a new one again... Thanks for the advice man i appreciate it...

 

I would also check the relay. Thats what my issue ended up being.