Doug Crall

I have a heater control problem in my 01 Dodge truck. My heater temp **** is more like a switch.
At about dead center, I have no heat, one click to the right and it is on maximum heat, one click back to the left and the heat is off.
I took the control out, and find a pot, and with an ohm meter, the pot looks like it works. I checked and found the mixer motor drive only works when the temp control is in the top dead center position, one click right and it goes full open, on click left back and it closes.

Is it a bad control or bad servo on the mixer door?

As always, thanks for your help
Doug

SIXSLUG

I thought the heat **** was vacuum operated, but could be wrong. My fan switch is 4 position but the heat **** turns smoothly IIRC. The blend doors can cause problems in the 01, perhaps you are correct in that assumption.

Kurt

Doug Crall

Kurt,
the temp **** on my 01 is a potentiometer , like a volume control. The control assembly has a spring and ball to add detents.

I am in hope that I am not the only on to have had a problem with this. The dealer is, as you can imagine, is no help unless I want them to repair it.

johnh

are you talking about the blower speed switch???

Doug Crall

No, The tempature control, on my 01 it's electronic too

infidel

I sort of doubt the mixer motor is bad if it does open and close.
Problem must be the switch although this is the first time I've heard of one going bad.
Never messed with one but it must be a rheostat, perhaps remove it and get some resistance readings before replacing.

johnh

this is what you need ....according to my manual it's not repairable, you have to replace the assembly

Busboy

I just took a look in my shop manual and it also says the sw assy is NOT repairable and must be replaced as a unit.. That is not entirely true. You may not be able to buy the part from the dealer but.... My truck came without AC so I installed the AC myself into it. I got some parts from the wrecker, the sw panel was one part. However when I came to put it all together the sw panel was from an earlier truck (95/96 I think) and had a cable driven temp sw so I used the original sw from my electric driven (heat only) and installed it (no modification) into the 95/96AC sw panel.
In this case I think my money is on the blend door actuator though. However changing the temp sel sw from a wrecker would be very easy and like I said it doesn't have to be an AC truck as the heat only are identical.

Doug Crall

Thanks Busboy, do you know what models and years they used that control panel?

Doug Crall

What Chrysler/Dodge used that switch assembly?

Busboy

I would say they were the same in the trucks from 96/97 up to at least 2001. It's easy to tell just look under the dash at the blend door actuator, if it's electric, that's the one you want.

Doug Crall

I thought the 2001 was the first year to use electronic control for the tempature ****/mixer door, and the earlier years used a steel cable

Busboy

My truck is a 2001 but my factory manual is a 2000 with a 2001 supplement so definitely 2000 had elex blend door but I'm pretty sure they went back much further, like I mentioned 1996?

Doug Crall

It's starting to sound like I should buy a new control from Dodge, and from what I have learned here is to buy one with out the AC control, save a few bucks and part it out to repair the unit in my truck.

I just wish I could be sure of if it is my control or the damper control.

Busboy

Parts are hard to find in the wreckers for the diesel trucks but don't forget the gassers use the same control. I'm pretty sure the elex blend doors went back much further than 2000. Can anyone confirm with a 97 or 98 that the blend door actuator is electric?
Like I said earlier I don't think its the control though, my money's on the actuator and if I had to pick between the two.... I'd pick the actuator.