I encountered a weird problem with my fan yesterday on my way home from work. I usually have it set to automatic and about 68 degrees. I noticed that it wasn't blowing so I increased the fan speed manually and nothing happened. I kept increasing it until it was set to max and the fan cut on and was blowing full blast. I tried to decrease the fan speed but it wouldn't respond, I even tried turning the unit off with no effect. I pulled into a gas station and turned the engine off completely but the fan kept blowing. Finally I got home and pulled the fuse to the blower and the fan finally stopped. I fiddled with it for a little bit with no luck so I disconnected the battery and let the car sit overnight. When I got home today I tried it again with the same results. Now the suburban is sitting in my driveway with the battery disconnected.

(Both the front and rear controls are automatic)

Does anyone have any suggestions???

It's a 2005 Suburban LT.

Thanks!!!

Beaseac

 

Sounds like a bad blower motor control processor. Which is basically just a solid state blower motor resistor that changes fan speeds depending on what the hvac controls commands it to do.

The control processor is located under the passenger side of the dash and is screwed up near the blower motor

 

Thanks shwnvw! Do you know if this is something I can pick up at Autozone or Advance Auto? Is it difficult to replace?

Thanks!

Beaseac

 

Super easy to replace, And the part is more than likely a dealer item, but it wouldn't hurt to ask autozone

 

I installed the part on Thursday. I ended up purchasing it from my local Chevy dealership for about $120 after tax. I could have ordered it for a little less but probably wouldn't have gotten it before memorial day weekend. I did notice that RockAuto (or something like that) sells a different item that supposidly replaces this one. I figure if this goes out again I'll give it a try.

Thanks for your help!

Beaseac

 

Had the same problem where as my suburban was turned off but the blower was still running. I replaced the resistor an everything went back to normal operations...

 

Now I'm having problems with the blower not turning on, put a new blower motor but problem still persist... Fuses appear ok, could it be a relay ?????

 

Troy Tauzin Welcome to the forum
IT could be relay or possibly the switch

 

I'm having the same issue right now. I've replaced everything and its still not working. did you ever figure it out?