HVAC fan not working

Retep · Post by **Retep** » Mon Mar 21, 2005 6:44 am

Went out this morning to start the truck and let the de-frost melt the frost off the windshield and the fan would not work.
I killed the engine and checked both fuses labeled HVAC in the dash fuse panel and they were fine. Hit the ignition again and still no fan. Killed the engine again and checked the HVAC fuse in the engine bay fuse box. It was also fine. I then proceeded to bang on the fan motor housing a couple times cycled the ignition and it worked. I don't know if it was pulling and reseating the fuse or punching the fan motor that got it working.
Any ideas, or something I should be looking at/for???

top_sgt · Post by **top_sgt** » Mon Mar 21, 2005 7:00 am

sounds like the "punching the fan motor" got it working!! sounds like a bad motor.... check the wiring for voltage to the motoor!!

Retep · Post by **Retep** » Mon Mar 21, 2005 7:44 am

Help me, I am electronically challenged.

I have an old voltage meter or multi meter not sure which it is that a friend gave me. Do I set it for 12 volts DC and stick the probes in each side of the plug that goes into the fan???

SomeCrew · Post by **SomeCrew** » Mon Mar 21, 2005 7:47 am

My buddy has this problem on his s-10. When he turns on the heat when its cold out, he has to pop the hood, get out, and bang the fan motor once to get it rolling. He only has to do this when its cold out, and it doesnt seem to be a hassle for him, so he doesn't mind it. But he said he would have to replace the fan motor to fix the problem.

top_sgt · Post by **top_sgt** » Mon Mar 21, 2005 10:44 am

put the black lead from the meter to ground. the colored lead goes to one of the wires to the fan. one should have voltage, the other should not!! the 12-14 volt scale should be fine!! hope this helps!!

Retep · Post by **Retep** » Mon Mar 21, 2005 11:10 am

Thanks. Will try that if it quits again. Perhaps it was just a fluke. God knows my truck has had plenty of those

aa21830 · Post by **aa21830** » Mon Mar 28, 2005 12:12 pm

The motor's not that bad to replace if you have to. I got a replacement from Autozone, maybe $30 which included the fan. I've also had to replace the fan switch resistor when the lower two fan speeds stopped working ('96 Sonoma). It's even easier to replace - under the hood near the fan.

Yellow Hammer · Post by **Yellow Hammer** » Wed Mar 30, 2005 11:28 pm

Make sure the batteries are good in your multimeter. If not, you will get false readings.