2004 Denali Ventilation

chew · October 17, 2007

I recently bought a used 2004 Denali, 70K miles. I noticed that only hot air blows out the passenger vents no matter what I have the passenger dial temp set at. The driver's side vent work just fine - if I set it on 60 I get only outside air. If it's set on 90 I get lots of heat. However, the passenger side still blows hot air if I set the passenger control at 60. As the outside air temp is slightly cool this time of year I have turned off the A/C. I read the one post about disconnecting the battery for 10 min. then starting the truck and don't touch the controls for at least 1 minute. Might this work in my case? If this doesn't work, what else can I check?

2nd - When the truck is moving I can feel something in the steering, but I'm not sure what it is. It is very slight and does not have any specific pattern. I am trying to figure out if it is wheel bearings, CV joints, or something loose in the front end, etc. A local mechanic told me that GMCs are known for, I think he said, steering arms that need replaced periodically as they were out. Is this really an issue? Can you offer any advice on what it may be, or not be, and what to check? Thanks!

Oh, one more thing. Is there anything I need to do if the battery is disconnected/replaced (ie resync keys, or reprogram anything or does the truck take care of reinitializing everything? Thanks!

Dave

xx_ED_xx · October 17, 2007

More then likely its the blend door actuator. Just done one on a trailblazer

atboley · October 18, 2007

try disconnecting you battery for about 10 minutes and reconnecting it, this will make the actuators recalibrate, if it still doesnt work right then you need to replace the temp acuator for the passenger side

GMTRUCKTECH · October 18, 2007

try disconnecting you battery for about 10 minutes and reconnecting it, this will make the actuators recalibrate, if it still doesnt work right then you need to replace the temp acuator for the passenger side

Yes do the batt disconnect first you got a 50 50 shot but more them like your right temp actuator is binding. Also there is a another trick in my hat go to the right side of the dash where it meets the door when closed. Open the door and take the panel off the dash. It's a small panel behind it is alot of connectors. With your key out of the ignition dissconnet all the connectors check for any loose pins repair as ness. Reinstall all connectors and restart vec. Sometimes unpluging and repluging fixs the issue if not replace the actuator. There is also a update for the hvac module to improve door sweeps on the actuators.

The knocking noise is the int. shaft for sure very common!

chew · October 18, 2007

try disconnecting you battery for about 10 minutes and reconnecting it, this will make the actuators recalibrate, if it still doesnt work right then you need to replace the temp acuator for the passenger side

Yes do the batt disconnect first you got a 50 50 shot but more them like your right temp actuator is binding. Also there is a another trick in my hat go to the right side of the dash where it meets the door when closed. Open the door and take the panel off the dash. It's a small panel behind it is alot of connectors. With your key out of the ignition dissconnet all the connectors check for any loose pins repair as ness. Reinstall all connectors and restart vec. Sometimes unpluging and repluging fixs the issue if not replace the actuator. There is also a update for the hvac module to improve door sweeps on the actuators.

The knocking noise is the int. shaft for sure very common!

Thanks much for the info. I will try the battery 1st. I like keeping it simple, if at all possible. I do believe you are correct though that it most likily will not fix the problem. What is the best way to access the actuator to get to it if it needs replaced? How can I get an update for the HVAC module and how would I load it? What is the update issue with the HVAC controlling door sweeps? What is the int. shaft? Is this the rod with grease fittings that connects the steering linkage to the wheels? Sorry for all the questions. Again, Thanks!

Dave

atboley · October 19, 2007

unfortunatly the actuator for the passenger side is located on the top side of the hvac case, which meens you have to pull the dash back to get to it, it is not exactly an easy job your first time.

the noise you may be talking about might be the steering shaft, they dry out and will cause a clunking in the steering column, its a very common problem and is pretty is to rep[lace... the shaft it the part that connects to the steering column at the bottom and goes thru the firewall. just make sure the steering wheel doesnt move when you disconect it...