Any help at all would be greatly appreciated.
I have a 2004 Chevy Silverado Z71. Also, have the option for electronic dual climate control ac/heat.
I had a dead battery a couple of weeks ago and charged it back up. Then few days later again, battery dead. so i thought well its a 2004 battery so it may be bad. I had a spare battery in garage so i put it in the truck.
With new battery, a few days later, another dead battery. Charged it again and took it to auto parts. Had them check the battery and all was good. charging system ok also.
So next time battery was dead, I charged and hooked up to see if i could read current from system. I did. after looking and hearing, I noticed the blower fan for the ac/heater is running all the time. with key off and nothing on, you can feel air coming out the vents. I checked all the options of the heat and ac. to the floor, vents, defrost, and all ok. no problems. other than fan always on with or without key turned on. I disconnected the battery and left it off for a couple hours then reconnected. Thinking anything that may have error from low voltage would reset? Reconnected the battery and fan comes right on.
Has anyone ever had this issue or have any ideas? Plan to track wiring down and make sure a relay not stuck or wire cut shorting out to something.
Again, any help would be great. I have used these forums before with lots of success. thanks in advance to anyone willing to take the time to type up something.
Chevy Trucks 4 Life.

 

sounds like the blower motor resister went bad it will go bad and keep fan on not sure where it is on yours but it has to be in the ductwork normally on firewall

 

Info for this problem. I found some info on another site. I thought I would post info incase somebody needed info.
Looks like when you have the electronic climate control you dont have the resistors under the dash. You have a blower control module. this module had a number (1p)52495874 on it. Blower plugged into it and another plug went to fuse panel.
Opened up the module and found nothing I could fix or replace. Have to order a new one.
Found part number 52495874 online at gmpartsdirect.com they sub'd to part number 89018778. Must have found an issue
with the old part. Imagine that! Ordered part. will post info once i test new part.
price was about 75 bucks with shipping.
FYI.... to remove, remove three screws holding the cover under the dash of pass side. One screw was really hard to get out.
once cover is off, fan and module can be seen. two screw hold module in and come right out. fan plug was hard to figure out. so after standing on my head, the fan comes right out. just had to pull on a lock tab and twist motor. came right out. unplugged fan and reinstalled. module had a heat sink that when installed goes up into the air path. I guess to sense the air temp for the auto climate control? unpluged the module and battery was fine this morning.

 

Hi, I saw your post back from 2008 on the blower always on issue. I have an 06 LT# Silverado with auto a/c and my blower runs with key out. Did replacing the blower control module solve the issue?
Thanks,
Mike in Alabama