Heater malfunctioning

[SmoothRide]

The heater in my otherwise perfect 2007 LaCrosse has developed a strange malfunction. When the temp knob is all the way to the left (as for max A/C), the air flow is strong. However, the further to the right the knob is turned (into the red), the weaker the air flow becomes until nothing comes out anywhere, no matter where the output dial is set.

Is this a problem with an "air dam" getting stuck or not operational? When the temp knob is about midway, the air is hot but it blows weakly even when the blower is on high, so I don't think it's anything to do with a clogged heater radiator core.

The A/C works great as long as I keep the temp knob all the way to the left (blue), so I didn't realize there was a bad surprise awaiting until the weather got colder.

Thanks!

 

[SmoothRide]

The heater in my otherwise perfect 2007 LaCrosse has developed a strange malfunction. When the temp knob is all the way to the left (as for max A/C), the air flow is strong. However, the further to the right the knob is turned (into the red), the weaker the air flow becomes until nothing comes out anywhere, no matter where the output dial is set.

Is this a problem with an "air dam" getting stuck or not operational? When the temp knob is about midway, the air is hot but it blows weakly even when the blower is on high, so I don't think it's anything to do with a clogged heater radiator core.

The A/C works great as long as I keep the temp knob all the way to the left (blue), so I didn't realize there was a bad surprise awaiting until the weather got colder.

Thanks!

Dave

 

[DrivenDaily]

Sounds more like a clogged air flow on the heater core.

 

[SmoothRide]

Sounds more like a clogged air flow on the heater core.

Thanks! That will give me something that sounds more informed to tell the mechanics at the dealership.

Dave