heater help please!

[bigfeet]

I have a 98 Tahoe. The heater worked on and off all winter. I replaced that $30 resistor piece that goes on top of the box and it didn't help. By the end of the winter the heater barely blew at all. It was hot but the fan was almost totally dead. As soon as the weather got warmer, now it works perfectly. Any ideas. The colder it was this winter the worse it worked! Thank you

 

[Donnie Yukonie]

well sounds like your problem is actually in the fan itself not the heater . does the problem stay the same with the A/C

 

[bigfeet]

I never use A/C. Used it once last week it was fine. The crazy thing is all winter the heater was on and off, mostly not working or barely working. Then as soon as the weather turned, now it works fine. Blows hard as anything!

 

[SunlitComet]

either loose wiring or contacts in the fan switch or the commutator on the blower. you need a voltmeter to help narrow it down.