AC/ Heater not converting

Hello Everyone,

I have a 1996 V10 Dodge Ram 2500 and I have a problem with Heater/AC conversion in it and I can't seem to find the cause behind it. When I need to switch from the AC to the heater from the dashboard knob nothing happens, therefore every year when the weather gets hotter I do a conversion in the engine bay. I block the hot air hose and only allow the AC hose to enter the cabin, and during winter its the other way around. Ive got not control from the inside!

If you may know the cause of this problem please do let me know!
Much appreciated!

I would check your blend door to see if it moves. A quick way to test if its stuck or if the motor isnt working is to stick your head right by the gas pedal or cup holder and with the vents in the off position, move the temp select switch from one side to the other and listen for a motor. If you hear nothing than there is a good chance the blend door is stuck or the actuator has gone bad. If you hear a noise, then the actuator is moving, but there is no guarantee the blend door is until you look at it.

Seeing as you take the time to manually convert it, i'm guessing that means both your AC and heat work, you just have no control.

I'd give the blend door a check before really digging into anything else.

I did as you said, and I got nothing! I checked from the cup holder and underneath the gas pedals, also while the car is turned on and off to make sure that nothing is happening! Ive done some research and to fix the blending doors I have to take out the entire dash board, mine is cracked and it will get worse when I take it out. Is there a way to be 100% certain that its the blending doors so this fix will be a one time thing?

Thanks again for your help!

There is no 100% way to know before removing dash, but hey at least you can install a new one at this time as well, and take a look at your heater core.

My 2000 5.9l has a similar issue, I believe it is controlled by vacuum lines. What I do to make it switch when it wont on its own is turn it on to a/c then off for about 30 seconds then on to a/c and repeat until I get desired results. sometimes I will switch temp from cold to hot repeated until it works as well.

Unfortunately, the only way to tell if to take apart the dash. Mine is all cracked up too, and I dread having to take the facia off again to do anything becuase I dont think it will last.

The plastics are the number one ********* i've ever seen.

However, junkyards sometimes have dash's that are in better condition than yours, or you can pay a premium and get one from a place like rock auto.

I guess I just have to bite the bullet on this one and see how much damage its gonna cause to the dash and go from there! I found on Mopars' website that there are 3 doors, should I replace them all or a particular one out of the 3? There numbers are 7,8 and 11 according the photo at the attached link.

http://www.factorymoparparts.net/do...cat/blower-motor-and-fan-scat/?part_name=door

OdaiV10 said:

I guess I just have to bite the bullet on this one and see how much damage its gonna cause to the dash and go from there! I found on Mopars' website that there are 3 doors, should I replace them all or a particular one out of the 3? There numbers are 7,8 and 11 according the photo at the attached link.

DOOR for 1996 Dodge Ram 2500|4746211

Click to expand...

Part 11 is the blend door you are looking for. The others are vent control doors. The actual door will not need to be replaced. What might need to be replaced is the actuator, those are little servos that can go bad for absolutely no reason. Another possibility is the door is simply gunked up and is stuck or sticking.

I've had two blend door problems with one of the chevys I owned in the past. First was a buildup of gunk on both the door edge and the two pin things on either side that hold the door in place. The result was a blend door that was stuck and would take an hour of fiddling to get from hot to cold. The second time the servo died, that was my fault for not replacing it the first time. As with any electric motor, stalling it out kills it, and a stuck blend door IS stalling it out.

I would give the area around the blend door a good cleaning, and replace the servo, its not super expensive and in my opinion, worth the money to not worry about it giving out months down the road and me having to tear it all apart again.