Blower Motor Resistor

[hawch]

I just put in a new blower motor resistor in my 2004 ext cab Sierra. It has the dual manual climate control and AC. The fan speeds are still not working. I checked the blower fuse and it is good. Double checked the install and it is in correctly, really not much to it. No idea where to go from here.

 

Any ideas as to what the issue might be?

 

Thanks.

[kstruckcountry]

Plug and wiring would be the first thing I'd check. Sometimes they get too hot.

[steveo77]

The pigtail/plug can get hot and melt wires check it carefully. If I remember right GM actually makes the pigtail specifically for that purpose.

[Crash1]

Does the fan turn at all?

This spring my fan suddenly ran at near full speed whether the truck was running or not, the fan speed selector had no effect. I replaced the resistor module & everything was fine for 6 months, now the fan does not turn at all. I guess the next thing to replace may be the motor itself?

[hawch]

Yeah the fan does seem to run, but only really has any effect when on the highway or going 35mph+. If idling, not much air moves, but when I get going there is some decent airflow, even when fan is set to 0.

 

I will double check all the wiring in the morning, if I find something or figure out why this is happening I will post.

 

Thanks.

[steveo77]

Please do I'm interested...I've had to replace the fan before too but its not as common

[hawch]

Thanks Steveo77, it was the wire harness connector. It was not the wiring, but one of the plugs in the row of 7 was burnt out. I bought replacement harness for maybe $10 amazon, wired it up and all working. Now time to replace the air door actuator to get air to come out of the right places and I'll be all set.