2004 Sierra Defrost Default

[jesteronyer6]

I have been working on this isssue the last 24 hours. The other night my son and I took a ride in this truck and we turned on the defroster the next day the vent selector was not able to divert air to the other vents.

 

I have tried:

 

removing both HVAC fuses overnight

removing HVAC fuse while truck is running I was able to get air through main vents after several tries but after turning vehicle off the air defaulted to defrost

removing battery cables and shorting them to clear resident power

 

I beleive the actuator is still working but the system is all screwed up and out of calibration any ideas?

[txab]

I have been working on this isssue the last 24 hours. The other night my son and I took a ride in this truck and we turned on the defroster the next day the vent selector was not able to divert air to the other vents.

 

I have tried:

 

removing both HVAC fuses overnight

removing HVAC fuse while truck is running I was able to get air through main vents after several tries but after turning vehicle off the air defaulted to defrost

removing battery cables and shorting them to clear resident power

 

I beleive the actuator is still working but the system is all screwed up and out of calibration any ideas?

 

Have you tried following the procedure contained in this thread?

 

http://www.gm-trucks.com/forums/index.php?...mp;#entry897550

[jesteronyer6]

Trying post #11 if that doesn't work I will try post #12

[jesteronyer6]

Post # 11 = fail

Attempting Post # 12

[jesteronyer6]

Post # 11 = fail

Attempting Post # 12

 

 

#12 Failed.

 

I have been messing with this for 2 days I give up. Between the ABS problem and this I am spent. I replaced the drivers side speed sensor and cleaned the hubs on both sdies where the sensors mount but I am still getting low speed 10MPH ABS actuation. I pulled the fuse to keep the ABS pump from being damaged and I ordered two new hub assemblys I think the bearings and the abs sensor rings are shot.