Heater Blower Issue

[zalez]

Two days ago my heater just stopped working. No blower at all. This all happened when the temperature dropped from 40 degrees down to 0 degrees with a windchill of -25. I went to the dealer and they said most likely a resistor/module on the blower itself. Two days straight it wouldn't work. So I order the part. Now today, it's 25 degrees above 0 and the blower starts working!?!?! My question, should I still replace the part my dealer told me to replace? If a resistor/module goes out, would it start working again when it warms up?

[8.1HD/ALLISON]

Its probably the connection at the blower resistor module. They had some trouble with some of the terminals starting to get hot and melting the connector a little. I would check the connector. If it shows any signs of melting replace the connector pigtail and resistor.

[zalez]

I'll pull it and look at it. With just pulling the sound cover off, the exterior looks fine. Is there concerns with moisture on the newer resistors?

[RyanbabZ71]

When my resistor crapped out it stopped working on 2 and 3. They occasionally did work here and there for short periods of time.

[MikeNH]

No blower at all would make me reluctant to blame the resistor. I don't know how the 900s are but my 03 had 5 speeds- 1-4 were controlled by the resistor and 5 had a separate relay (labeled the high speed relay if memory serves). I lost 1 and 3 I think and the resistor fixed that but to loose all speeds (unless the 900s are different) I'd want to see if power was getting to the blower.

[rodram]

I agree here ... when my blower crapped out, my mechanic explained to me that if it was just the blower resistor, then it would still work on high speed only... the solution for mine was a completely new blower.

[zalez]

Mine seemed to dislike the below zero temperatures. Once it got to over 20 degrees it decided to start working again. Going on two days now and still working. It is very perplexing. At first when I thought it was fuse/relay, I did notice my truck has 2 relays, one for high and one for low. I just don't want to replace a resistor if it is working. I especially hate changing parts out when the problem seemed to go away. What would you guys do? Change the part, buy the resistor and just keep it on hand or just wait till it breaks again and stop trouble shooting all over?

 

Thanks guys for all your advice so far

[CapitalTruck]

Eventually I lost my blower at all speeds when my resistor went. Didn't even work on highest setting. I swapped it out for a new one and all was well, but now three years later it's starting to crap out again.

[timothymichaelmcnamee]

My 05 Silverado was having the exact same issue. At first it stopped working all together, then one and three stopped working. It's most likely the plug that inserts into the resistor. My ground wire connection in the plug was burned. I've since replaced it, and everything seems to be fine. Just my two cents. Good luck.