Its been a long time since I posted anything here, but this past weekend I picked up a 1998 2500 4x4 with a 5.9 gasser off of craigs list. Over all its a pretty decent pickup but I took it out for my first real drive and I notice I cant control the temp on the heater. The fan speed works and the position selection works but no temp control, just cold. My question is the heater control valve controlled with vacuum or electric or a cable? Where is the valve located? Any info on this would be great!

Jeff

 

It's a cable. Goes from selector to a blend door on the heater box. The blend door has a habit of breaking.

 

On a 98? What year did they do to the little servo motor on the bottom of the heater box?

 

2000 up . not sure about 99

 

They changed to the electrical in 99. The 98 is still cable controlled.