Fan Speed Switch

jake1530 · October 23, 2008

I just noticed yesterday that the fan shuts off when I put it on 3. The settings go from 0 to 5. I can’t say how long it has been like this since I hardly ever go past 2 in the winter. Occasionally all the way up to 5 to get ice off maybe. It’s a 2005 Sierra. Has anybody else seen this?

MS3DALE · October 23, 2008

Yep,Its probably the blower motor resistor,Theres a TSB out on it.

They want you to change the resistor,and also the connector for the resistor,Although the connector might look OK its common for the connector to burn or "crystalize" inside where you can't see it.

jake1530 · October 23, 2008

Dale thank you for your response. I hate to ask but what is a TSB?

MS3DALE · October 23, 2008

Dale thank you for your response. I hate to ask but what is a TSB?

TSB="Technical Service Bulletin" They help the technician diagnose and fix common issues or problems.

A "TSB" is NOT a recall,and if your vehicle is not under warranty it is considered a customer pay repair.

MS3DALE · October 23, 2008

BTW....If you call your dealer they "should" be aware of this issue,Its been a common problem for a couple years now.

jake1530 · October 23, 2008

Thank you very much Dale. Just curious, is that inside the fan speed unit or someplace else in the truck, maybe near the fuse box? Yup it's out of warranty thats for sure. Thanks again Dale for your time.

MS3DALE · October 23, 2008

It's in the lower heater box case,Inside the truck under the I/P on the passenger side.

Your gonna' need to remove the "husch panel" that covers the heater box up.

jake1530 · October 23, 2008

thanks Dale.

bigbengalbubba · October 23, 2008

When I changed mine I used these detailed instructions (with pictures). The year was different but basically the same and it helped a lot.

Blower motor resistor replacement

MS3DALE · October 23, 2008

^^^^^Thats perfect!!^^^^^

jake1530 · October 23, 2008

Thank you, thats great, take care.

MS3DALE · October 23, 2008

OK,Hope thats your problem.

jake1530 · October 23, 2008

Yup, that was the problem and took care of it this morning. I just wanted to say thank you to you both, Jake. Also KY, I didn't have a blower motor cover on my motor. I just had to remove the outer cover, the blower moter was exposed.Thanks again.