2004 rear fan

[Gnarley]

I'm new here and have a 2004 Yukon SLE w/130,000 miles. Barely any problems until now. I have Auto climate controls front\rear.

The rear A\C has the fan blowing on high with the engine running and I'm unable to adjust it. It does not operate with the engine off. I suspect it's the Blower Motor Resistor.

Can anyone validate my diagnosis and perhaps suggest the replacement part number? I found a Standard Ignition RU-807 Blower Motor Resistor for $219.00! That seems a bit high and believe there is an alternative for much less.

Thanks

 

[Scottydoggs]

do you have controls on the back of the console, if so maybe its set up to be in control. try changing the fan speed from back there if you have em.

 

[Rocket Man]

What he said, but maybe overhead controls for the rear so the 2nd row passengers can adjust it. That’s what mine has.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics, please.

Generally, when the blower speed resistor fails, one or more fan speeds no longer work, but I've never hear of not being able to shut the fan completely off, due to a fan blower resistor failure. Other folks more familiar with the 2004 model year will chime in

 

[Gnarley]

 

[Gnarley]

The front actuator seems to work fine, however, the rear actuator seems to go to the A/C side no matter what. I removed the cover to see if I could trick it to resetting and it seems no matter what it opens the door to the A/C.

Thoughts?

 

[Rocket Man]

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If you set all 3 controls to no fan speed it still blows on high? Did you try the reset process? Try this:
https://www.tahoeyukonforum.com/threads/recalibrating-hvac.81057/

 

[Fless]

^^^ THIS. Or if you have access to a Tech 2 it can do the reset.

 

[Gnarley]

If you set all 3 controls to no fan speed it still blows on high? Did you try the reset process? Try this:
https://www.tahoeyukonforum.com/threads/recalibrating-hvac.81057/

Actually no, it has now stopped blowing and operates as it should! I did nothing other than come out the next day and started it and the rear did not run. Then after a while, the fan came on and the blower was running and seemed to be trying to run as if on Auto, it wasn't high or off, it was like it was hunting for a speed to blow for maybe 3-5 minutes and then stopped. Then, for an hour or so as I worked on the Temp actuator I had full manual control from the front or read fan speed. It seems really strange?

 

[Rocket Man]

Actually no, it has now stopped blowing and operates as it should! I did nothing other than come out the next day and started it and the rear did not run. Then after a while, the fan came on and the blower was running and seemed to be trying to run as if on Auto, it wasn't high or off, it was like it was hunting for a speed to blow for maybe 3-5 minutes and then stopped. Then, for an hour or so as I worked on the Temp actuator I had full manual control from the front or read fan speed. It seems really strange?

Sounds like it did a calibration itself. That’s great.