1995 GMC Sierra heater blower doesn't work?

[Bri]

Yesterday I noticed it didn't work on 1, 2, or 3 only on Max. Today even on max it doesn't work but it makes the battery gauge dip way down, from 13.8 to about 7. As soon as I turn the switch back to 3 the gauge jumps momentarily to around 17 and then back to 13.8. I'm not sure if its just the resistor or if was just the resistor and now its the motor. Any help would be greatly appreciated!
Thanks
Just wanted to add, I can hear something engage when I turn the switch from off to 1. Not real loud, but some warm air is coming out, but its not being blown out.

 

[(A+)]

Sounds like it needs to be replaced.

 

[paul h]

The blower motor is controlled by three items...the fan switch in the heater controls, a low speed blower resistor and a high speed relay. It sounds like the resistor and the high speed relay are both bad but you could also have bad fan switch as well. Best to test the circuit and each component as well as the fan motor or figure on replacing all three. Try running an appropriately fused power source jumper wire power directly to the motor and see if it works OK.

 

[helpful bob]

To me it sounds like the resistor is bad but it also could be that the blower motor windings are over heating or shorted out bec the voltage drops like that.Easy fix either way and a good U pull auto wreckers should have a few vehicles you can pull the resistor and blower motor from and I'd test the blower motor on the spot if possible and the resistor too , plus I'd get more then one resistor.



Hope that helps and best of luck.By the way check the wiring and connections for hot spots and damage bec it's quite common for those circuits and you might want to pull a whole blower motor etc assembly.