Can anyone explain to me why the heat would blow hot air out the upper vents, but COLD air out the bottom to the feet? My rear heat doesn't work and it turned off, but the front? There is HEAT... but only out of the vents. And Cold air comes out at my feet whether I have the **** turned to it or not.

I swear I am going to get frost bite this year!

 

Sounds like the diverter door is stuck/not working properly then. I think the 01-03 trucks have electronic actuators for them rather than vacuum, so I'm not sure what all you can do to trouble shoot them.

 

I had originally thought vacuum, and I know that I have a pin hole in my evap line that runs under the truck, but all the other line is fine, SO, I ruled that out.

Ok, so now... electronic actuators... hmmm. Time to research!

 

98-00 still used vacuum. I think I've seen people talking about replacing those actuators on here somewhere.

 

if it is a blend door issue, I think it is driven by a cable. Mine got stuck because the cable was kinked somehow. I can also feel resistance when trying to turn from heat to cold on the **** but from cold to heat, it turns fine.

After unkinking the cable, the termperature **** turns freely and smoothly in both directions and my heat is now working.

 

This seems to be the easiest place to start, so I will give this a checking into.

 

I'm not sure that the 01-03 trucks have the cable like the 98-00s did.

 

If you have a 2002, it should have electronic actuators. The puzzling thing is having a difference in temperature from top to bottom. Can you clarify something - when you say top vents, are you referring to the defrost vents, or the vents on the face of the instrument panel/dash?

There is a mode door actuator if you look up under the dash from the driver footwell, right along side the hvac unit which sits in the center. The actuator is an electric motor that rotates a cam-wheel that is double sided. The motor side of the cam has a track that drives an extension arm connected to the defrost door. The other side of the cam has two tracks, on each for positioning the front panel and floor vent doors.

If I remember right, there's a similar motor on each side of the central hvac unit, that positions blend doors to control the temperature of each side of the system. Look for drivers side motor just a little further up and back of the mode door actuator. And the passenger side blend door actuator over on that side.

If you can see these, look at them while adjusting controls. Look for their shafts/cam to rotate smoothly without binding. Again, there are no cables or vacuum motors on this model year, that I know of.

 

The facing vents blow hot. I don't know about the defrost, I have to check, but the feet blows cold! I will have to check that.

Everything I see so far, requires disassembling the dash and I don't want to do that if I don't have to. I just want heat.

Also, I might add, that the facing vents are the ONLY heat source. Everything else blows cold in that truck!

 

There are some things you can do without disassembling the dash. If you look up under the dash you can access the mode and blend door actuators. You can watch those while you adjust the controls and see if things are moving correctly. You can even get those actuator motors out and replace them without doing the dash.

For the rear heat/ac, there have been a few issues with the blend door. What happens is that there is a coupling link that goes between the actuator motor shaft, and the pivot/axle of the blend door. That coupler has a small stop tab formed into the side of it that can break off. When that happens, the motor over-rotates the blend door and eventually the door breaks. Several people have come up with various fixes for that. You can buy a new (improved) coupler at the dealer, and repair the door, and put it all together.

Search the forum. One thread with useful info: https://dodgeforum.com/forum/1st-gen...orks-fine.html

You can search and find others, too. Before I did that repair I was kind of put off by the idea of tearing into the rear unit, removing the third seat, etc. Turned out it was pretty easy overall; it's not near as bad as it looks.