Blower Not Shutting Down

[cajun]

2006 Envoy Denali

V8 w/DoD

 

Every so often when I kill the engine and exit the vehicle, a blower keeps running. It will keep running until I get back in, put the key in the ignition and turn to on; then it cuts off.

 

I am planning on bringing it in to the dealer to have it checked out, BUT naturally it is an intermittent problem and i can bet it won't happen when its in the shop. I'm wondering if there is a TSB relating to this problem that I can point the Service writer to that they can look at to fix the problem without having to actually see the problem.

 

Great forum

 

PS: Anyone know what has happened to the GMC Envoy forum? It's been dead for awhile now?

 

cajun

[Draenor]

Are you talking about the radiator fans and the HVAC blower?

[cajun]

Are you talking about the radiator fans and the HVAC blower?

 

Sorry, should have been a little bit more clear here. It's the HVAC blower. Doing some research, it appears it may be something associated with the "afterblow". Apparently, the system can be programmed for the afterblow to run at different times after the engine is shut down to dry out the system and prevent mold build-up which gives out the smell in some HVAC's upon start-up.

 

BUT, this is suppose to only be programmed with permission of the owner because once turned on it can't be turned off.

 

I'm still not sure this is the cause, only a possibility.

 

cajun

[atboley]

its the afterblow function, dont worry about it... it does nothing but help your a/c from smelling like mold...

[cajun]

its the afterblow function, dont worry about it... it does nothing but help your a/c from smelling like mold...

 

 

Thanks KNowItaLL, I'm feeling a little bit better about the problem. One more quick question for you if you don't mind. Considering your response to another thread with a similar problem, you posted the service bulletin concerning the replacement of the LPM. It also stated that the problem was fixed for all deliveries after March 03, 2003.

 

Could this be causing my problem or do you still feel that it is the afterblow. My reason for asking is because from the research I did, the afterblow should not have been turned on (Envoy bought new of the lot). Although I did have some issues with HVAC that required some dealer repairs.

 

Just throwing this out there, like I said, I think you are right about the afterblow, mainly because of how it will shut right off if I put the key back in the ignition and just turn it on without even cranking the engine.

 

Thanks again for you imput,

cajun

[atboley]

here is the description of how the afterblow is supposed to work, if it isnt doing exactly this then maybe you do have a problem... but if it stops when you turn the key on i would think that it is the afterblow, because if the blower controller is bad it will continue to run no matter what you do... also the afterblow is turned on by programming the hvac module, so if you had previous hvac concerns they may have reprogrammed it to try to fix somthing else and ended up turning on the afterblow also...

 

The blower motor will turn on approximately 10 minutes after the vehicle is shut off. The blower motor will run continuously for 10 minutes at a 30% duty cycle. The afterblow function will only activate if the air conditioning compressor was engaged during conditions of high ambient temperature. If the vehicle is started within 10 minutes of the last key off, the afterblow function from the previous key cycle will be cancelled.