Cab Heat issue.

[Duramaxduner]

Hey guys I'm pretty new here. Its getting pretty cold out lately here in Michigan and I have been running my heat more and I just noticed that every vent on the passenger side blows out freezing cold air while the drivers side blows out the heat it is supposed to. I have the passenger side turned all the way up to 90 on the climate control and it's still ice cold. Any idea what that could be? My engine is running around 165-170 degrees.

 

[Rikter]

I had this before. Did you reconnect batteries lately? The digital stepper motor has lost it's zero point. Try setting everything to the setting you think it thinks it's at ie: full cold on vent or wherever it blowing. Then leave it for at few starts & stops. 3 at least. Then I turned mine to off & turned key on & off 3 times. seemed to reset. The other way is to disconnect batteries & then re-attach with ONE firm connection. It's the bump on/off/on/off that messes it up. If none of that works the stealer will want to change that stepper motor.$$$

 

[Duramaxduner]

I have not messed with the battery's lately but I will give that a shot! Any idea where I could get one of those stepper motors if need be?

 

[DAVe3283]

The blend door module failure is somewhat common. You can get the part from the normal part sources (dealer, websites), but it is a pain to replace.

Since it has lost the zero, that means the potentiometer inside it is bad, and it will just do it again. From what I have read, keeping the settings off the extremes (not full hot or full cold) will help prevent it from losing alignment again, but it is just a matter of time.

Hopefully you can get yours to reset.

 

[Duramaxduner]

Well if it is just going to keep doing it then I am going to have to replace it. Any idea how to do it and where under the dash is it located? Near the fan?