Blower quits blowing AC when driving sometimes

[lamopar]

My 2003 Dodge Ram just quits blowing AC or anything when we are driving. It usually takes some time before it quits. The blower motor is still kicking but but there is no air coming out the vents. I checked the recirculation door and it is in fine condition and works perfect. I checked the hot/cold blend door and it works. The door for the passenger side for heat works as well. The blend door for where the AC or heat goes, up or down, seems to be working as well. I can' t figure out how it works most of the time but when I am driving it just quits. You can hear the blower motor running full speed but I can't find any air coming out anywhere. I have pulled the blower motor and looked and it seems to be ok. I can't find anything blocking the passageways. Any ideas?

[PSU1999]

We have a 2005 Dodge caravan that will sometimes do this same thing! Additionally if it sits running in park for too long during hot humid weather all the dash board lights will turn on and although the blower is still running the A/C quits so the air is just being circulated but not cooled.

[thomasmnile]

Double post! !!@#$%^& Internet..............

[thomasmnile]

Terryallan wrote:
Often, Especially on Dodge products. the doors will go the the defrost default position when you are towing, especially while pulling a hill. Why? Hard pulling causes low vacume pressure, and when the system loses vacume. It goes to the default Defrost position. It goes there, so IOF you lose all vacume. At least the defroster will work.

The climate controls on a Ram diesel are not vacuum actuated, at least 2004 MY and later. The blend doors are (about 4 total) operated by 12v motors/servos attached to plastic shafts on the doors. The shafts are notorious for breaking. To the OP: While blend door problems are a possibility, I would also consider The climate control module in the dash; in a 10 year old truck a problem with that module (electric/electronic) wouldn't be surprising.

[thomasmnile]

Terryallan wrote:
Often, Especially on Dodge products. the doors will go the the defrost default position when you are towing, especially while pulling a hill. Why? Hard pulling causes low vacume pressure, and when the system loses vacume. It goes to the default Defrost position. It goes there, so IOF you lose all vacume. At least the defroster will work.

The climate controls on a Ram diesel are not vacuum actuated, at least 2004 MY and later. The blend doors are (about 4 total) operated by 12v motors/servos attached to plastic shafts on the doors. The shafts are notorious for breaking. To the OP: While blend door problems are a possibility, I would also consider The climate control module in the dash; in a 10 year old truck a problem with that module (electric/electronic) wouldn't be surprising.

[the_happiestcam]

Used to have a 2003 Dodge that would do the same thing, stop blowing cold air after awhile. I would just roll down the windows part way for about 10 seconds then roll them back up - it would start working again.

[_40Fan]

I don't know of a single 3rd Gen that wasn't delivered from the factory low on Freon.

[45Ricochet]

lamopar wrote:
I wish I had figured it out before tearing the dash all apart checking the recirculation door.

I could never do that or watch it being done. Just to painful looking for me. As a side note, had it charged and dyed 2 years ago. Still blowing cold air but now the fan on high is louder 🙂 Forgot to check to fan on high with the heater going.

[ib516]

The system in an 03 Cummins would be run by electric actuator motors, not by vacuum.

[PaulJ2]

wnjj wrote:

Greg B wrote:
If the blend doors are all working, maybe the a/c evaporator is freezing up. Maybe check the freon pressures?

This happened in my brother's S10 once in a trip in high humidity. It would slowly lose flow until there was almost none. Turning the heat on full blast would bring back the flow. Each time we stopped there was a huge puddle of water from the evaporator drain.

Same here. While driving on a hot day the air flow would gradually drop to nothing but a little warm air. Shut of AC for a few minutes and everything back to normal. Checked AC charge, was a bit low but in spec. Topped up the freon charge, no problem since.
99 Jeep Cherokee.

[lamopar]

Thanks for the tip. I figured out today that the system is freezing itself out. I shut off the air conditioner and it started to blow harder in a couple of minutes. I am going to take it in and get it topped off and have the system checked out. I have had the truck ~4 years now and I guess it is time. I wish I had figured it out before tearing the dash all apart checking the recirculation door.

[Kjun]

I hse a 2003 3500 that has been doing this for years. Check your freon charge. I have the dual control and keep a thermometer in the air duct. When the outlet air gets below 40 degrees F. I add a little heat to one side of the systel to keep the evaporator from freezing. I usually have to add a little freon 134A every couple years. Dodge runs a evaporator noisture sensor to cycle the compressor. If the evaporator freezes there is no moisture for the sensor to read. The low freon charge is taking the low side head pressure below the freezing point for R134A.

[wnjj]

Greg B wrote:
If the blend doors are all working, maybe the a/c evaporator is freezing up. Maybe check the freon pressures?

This happened in my brother's S10 once in a trip in high humidity. It would slowly lose flow until there was almost none. Turning the heat on full blast would bring back the flow. Each time we stopped there was a huge puddle of water from the evaporator drain.

[larry_barnhart]

We had a 91 chev van and it would stop blowing cold air when we had a hard side wind blowing. If would come back as we changed directions. Of course this only happened on a vacation trip .
chevman

[lamopar]

Well so far I have determined it is not the actuator for the recirculation door nor the door itself. The two motors that change the doors from the air conditioning to the heater core are working perfectly. The unit that moves the air from the floor to the defroster is questionable. I may change that one out but the door is just fine. So since it works most of the time and there is no vacuum used in the 2003 version I think I am stuck with just replacing the motor that controls the door and hope that is it. I did notice when the blower is full on the motors have a tough time moving the doors fully open or closed. If this was a full time problem it would be easy but since it is not, well it is hard to locate.