Hello everyone,

I'm trying to find a solution to a problem, not sure ifanyone else has experienced this. Irecently bought an '07 Aspen. P3441 code was remedied at dealership last week. They replaced the #6 solenoid. All is good, so I thought. This past weekend I had a 200 mile trip to make. The air conditioner quit pushing out cold air about 150 miles into the trip. The blower still worked, but the air box sounded like it was sealed. No matter what air-direction button I selected, no air would exit the vents. I could tell that the air was cold, as you could still feel a tiny bit of air escape around the floor and behind the dash. This seemed to coincide with how fast I was driving. As I neared my destination,we were doing 75-85 MPH instead of 70-74. Although, slowing down didn't fix this problem.

At my destination, I let the truck sit for about 30 mins, got in and did some driving around town at 35-45 MPH and everything was fine. This seems like a vacuum leak to me. Not being able to change the outlet of the cold air. I don’t know if there is a way to test for this at home? Did the dealership not connect something completely when they changed that solenoid that would cause a vacuum leak at speed? Also, this is the 5.7 Hemi engine if that makes a difference. Any help would be appreciated. Thanks!

 

I understand how you're connecting the dots, but these sound like unrelated events. Replacing an MDS solenoid requires removing the intake manifold, a bolt or two, and a wiring connection.

If the blend door / actuator needs to be replaced, it's a big job, and requires taking apart the dash. Is everything still working? You seem to indicate that it's working now...

 

My thoughts behind this problem was a vacuum leak. I guess I assumed that the blend doors were vacuum operated. Since this issue never occurs around town and only at high speeds. I thought maybe there was a vacuum leak, since they removed the intake manifold to replace the solenoid, I thought there could be a leak in the intake manifold seal. Guess I need to see if anything is vacuum operated behind the dash. Thanks

 

Seems like the evaporator was frozen. The blower wheel is behind the heater core and evaporator. A frozen evaporator would block the airflow until it was allowed to defrost. Why did it freeze? There is a temperature sensor in the evaporator that is supposed to shut the compressor off if it gets too cold, but with low cooling load and low blower speed it could freeze. I would not worry about it unless it happenned again. Ambient temperature humidity and blower speed all come together to create the perfect conditions for this to happen.

 

There is a technical Service bulletin on this issue. basically the compressor is not cycling properly. the dealer can fix this for less than $100. I know because I had this happen.

 

I had the same problem, the evap frozen, same as Sine mentioned. There is a tsb that adds a resistor to the evap temp sensor to address the issue