2004 Chevy Impala

Hello! We just purchased a 2004 Chevy Impala. We just noticed when we went to use the heat that while both sides are blowing air, only the passenger side is hot. Any idea? Someone mentioned to me that it is possible the heating coil has a blockage? Or it could be some door is stuck? If you turn the defrosts on and the floor heat on it is the same issue. Cold on the drivers side and hot on the passenger side. :confused:

sounds like the temp door that blocks off heater core or evaparator core is stuck partially or completely on heater core. could also be the switch or the actuator under dash

sounds like the temp door that blocks off heater core or evaparator core is stuck partially or completely on heater core. could also be the switch or the actuator under dash


Thanks for the reply! Is there an easy fix for this?

Is this a "DUAL" system? If it is, then the temp actuator on the side you are getting no heat is the problem...

Is this a "DUAL" system? If it is, then the temp actuator on the side you are getting no heat is the problem...

Yes it is dual. So a simple clogged heater core isnt the issue. :/ Is this an easy fix?

Well, you have to be sort of a contortionist to get to the actuator.....

Take it out of dual mode, and command full hot then full cold.....there usually is a silver ring on the side that shows it is moving....

If it doen't move, I"m guessing the actuator....could be the control head, or even a problem with the temp door(broken or binding)...most likely the actuator....just two 5.5 mm screws hold it in place....once removed, grab the linkage to the temp door to make sure it moves....should feel a difference in temp when you move it...

Thanks Tech. I read a post on a google search while looking for pictures of replacing an actuator. It stated at the end that the actuator will need to be rrecalibrated and showed steps to do so. Now my question is..should I just try a recalibration? Cant hurt right? We just purchased this vehicle and it was not working when we got it so not sure if maybe a simple thing like this may work? If not gonna have my daughter's bf change it out. :)

Couldn't hurt to try.....

But all GM cars are different.....some you need a scan tool, like a Tech II, to recalibrate....

In some cases, it's a simple as removing the HVAC fuse....have to know the procedure that is specific for your vehicle...