2nd Gen Non-Engine/Transmission Heater full on

[AWadsley]

Hi

99 chassis/cab 3500

Heater is at full output no matter where control is (except off), the air is directed where it is supposed to but it is hot.

With ignition on the actuator has the feel like it is hunting and not going to one position and staying there.

Is this a blend door or the actuator or linkage?

Thanks for any assistance.

Awad

 

[Demons_Ram]

Not sure on your 99 but my 01 controls the blend door with an electric servo motor (all the other doors are vacuum controlled). It's located on the bottom of the HVAC box over the right side transmission tunnel. The wires for it split off of the blower motor resistor and go down under the HVAC box.

There are no hot water/coolant flow control valves on these trucks between the block and the heater core, so hot water/coolant is constantly flowing through the core. :{

If you need temporary relief until you get the blend door problem fixed, you can by-pass the heater core feed by a U-turn hose on the block. or install some type of shutoff vales in the heater core lines. Oo.

If it's the "interposer" (plastic coupler) between the servo motor and the blend door that's stripped, try this link
Dodge Ram 1995, 1996, 1997, 1998, 1999, 2000, 2001, blend door auto AC heat replacement part

 

[AWadsley]

Thanks Demon

I removed servo yesterday and coupling was split and stripped. Not wanting to wait I epoxied back together and reinforced with a metal band type clamp.

Working great now.

Thanks again

 

[Demons_Ram]

Glad to hear it was fairly simple.

 

[Schweitee]

2K 2500 Interposer Problem

Demons_Ram & AWadsley

Thanks to AWadsley for clearly defining the heater problem with your '99 and Demons_Ram for outlining the solution and providing the link where I order a new Interposer for my 2000 RAM. A $35 fix compared to hundreds of $$s had I brought it to a dealer. You've gotta love this forum. It's saved me thousands of $$s over the years. THANKS Again!!!