My '98 has no heat, but there is water flowing thru the core. When I change the temp I can feel movement in the cable under the dash, but no noises like a door opening closing or movement in the heater box. All positions work, def, dash, floor, but no heat. The thermostat, water pump, all cooling system is new. The truck has heat and AC. This is my first and only Dodge of this era, so I have a couple questions.

When I turn the temp dial, there is no resistance at all, like it's not connected or moving anything, should it be like that?

Should there be any sounds coming from heater box when I change the temp for the heater? Like doors in the box or valves moving?

Thanks for any help

 

There won't be much resistance.... but yeah, you *should* be able to hear the door thump at one extreme or the other. Can you beg/borrow/rent a bore scope? Run it up where you can see the blend door, move the know, and see what happens? Dodge seems to have a reputation for the doors breaking......

 

You should be able to hear a hissing noise and well as something moving for a couple seconds. The dial should have a reasonable amount of resistance to it. It should feel like your spinning an o-ring. Pull the dial and see if its broke. You might be able to do that without pulling the dash. If its fine then your probably looking at a very large job for the blend door. It requires removing the heater box.