AC/Heater Fan

[Bucky]

My ac/heater fan has started running at irregular speeds lately. It will run fine for the first hour or so and then it will start acting funny. It may change speeds 3 or 4 times in one minute. Sometimes it runs so slow that I have to shut off the engine to hear it but it doesn’t stop completely unless the switch is off.

Does this sound like a fan motor problem or a switch problem?
Could it be something else?

Bucky

 

[Bucky]

I went to the bone yard and got a fan switch. No change so I guess I’ll try the blower motor.

Bucky

 

[argve]

Man I missed this post completely which in my defense I was moving during the time period it was posted - sorry about that...

Anyhoo.... I would say it sounds like a wiring problem. Reason I say wiring problem is it runs fine for a while then after things probably heat up it starts acting funny. Might want to check out the plugs first.

 

[Mastertech]

Perhaps it's a problem with the blower resistor. Some of those will melt the connectors. In fact I found a truck the other day that the blower wasn't working properly and the dealer had put and updated harness from the ignition switch to the blower motor.

 

[Bucky]

Where can I find the resistor? Is it on the switch?
BTW the fan isn't working at all now.

Bucky

 

[Bucky]

I cleaned the terminals on the plug down by the fan and put some OxGuard on it. It seems to run better now but I won’t know for sure till I drive the truck for a few hours.

Bucky

 

[argve]

let's hope that's all it was...

 

[2500cummins]

The blower resistor is on the bottom of the AC housing just left of the blower motor, it has a connector with four wires going to it. The resistor is in the ground side of the blower circuit, it should be easy to bypass in an emergency.

Jared

 

[Bucky]

Thanks guys. Jared, I found the resister and it seemed to be working fine but a corner of it fell off in my hand so I went to NAPA to get a blower motor and resister. The motor was $67 and the resister was 80 something so I got just the motor. I haven’t had a problem since.

Why doesn’t my signature show up? I filled it out and I checked the “Show Signatures” box under “Edit Options”. Do I have to make a donation to somebody’s Christmas party fund to get it to show up???

Bucky