2nd Gen Non-Engine/Transmission HVAC controls not working

[Bhale]

All i have are the defrosters :{



What should i start looking for?



The vac lines on the back of the mode control panel are connected and i can't find a leak there. The fan and all it's speeds are fine along with the temp control. When i turn the mode control knob from defrost to floor or recirculate (or any other position) i can hear something change very slightly but the air still comes out the top of the dash.



Help, it's winter time out here.....



Brian

 

[Joe G.]

Check the vacuum line on the passenger's side of the engine before it goes through the firewall. It may be melted closed somewhere. Check the portion of the line inside the connector. Mine was melted shut inside that thing so it could not be seen.

 

[Bhale]

Thanks Joe!



Are you talking about the elbow next to the transmission dipstick tube being melted inside? The hoses look fine... .



Brian

 

[Joe G.]

Yeah. There is at least one push together connector there. On mine it's straight. Maybe later it's an elboe. It's that is what it is it's simple to fix. Just cut the bad place off and push it back together. If not then you need to check to see how much vacuum you have, if any at the hose there. If you have good vacuum then you have to get behind the dash. It could be as simple as the hose being off the fitting below the glove box. I think one member reported that was his problem for the same symptoms.

 

[Bhale]

The fitting near the firewall, and the others under the hood, are all clear, no holes. I've got the dash apart and things look fine there also. They all have enough vaccum to hold my finger on them. Also, my PacBrake, which works off vaccum, is working fine.



Behind the glove box on the right is an actuator with a vaccum line going to it. I don't have any vaccum at the hose that connects to the bottom of the actuator and the diagram in my service manual shows the actuator as controlling the recirculating door. It looks like I'll need to trace that line back to where ever it leads but that doesn't look like fun. The dash may have to come out. :{ :{



I guess I'll start at it again in the morning...



Brian

 

[GAmes]

Check the actuator above and to the right of the go pedal. Mine had a pinhole in the diaphram and gave me the same symptoms you have. To check it, start the engine and select dash air. If the actuator does not retract, manually push it up. If you now have dash air then the actuator is bad. A word of caution here. If you have to replace the actuator be VERY careful when disconnecting it from the plastic arm that it is hooked to. The plastic will be brittle from age and poor design and easily breaks. To replace it you will have to remove the dash because it is also the hinge for the door that directs the flow of air inside the plenum. (Yes, I did break mine :{ ) That little plastic arm is also about $22 #@$%! .

 

[Bhale]

Good information GAmes! I'll check that out first thing in the morning.



Thanks

Brian

 

[BigIronRam]

Oh, a '96 working on defrost only? That can be real bad, check here:



http://www.dodgeram.info/tsb/recalls/720.htm



I hope that's not what's wrong with yours.



Robert

 

[Bhale]

Check the actuator above and to the right of the go pedal. Mine had a pinhole in the diaphram and gave me the same symptoms you have. To check it, start the engine and select dash air. If the actuator does not retract, manually push it up. If you now have dash air then the actuator is bad. A word of caution here. If you have to replace the actuator be VERY careful when disconnecting it from the plastic arm that it is hooked to. The plastic will be brittle from age and poor design and easily breaks. To replace it you will have to remove the dash because it is also the hinge for the door that directs the flow of air inside the plenum. (Yes, I did break mine :{ ) That little plastic arm is also about $22 #@$%! .

I found the actuator. Just as you said, if i pull the rod down the air changes to the dash vents. I can feel it start to move when i change the controls but it won't move on it's own, however, i can pull it down and it'll stay there. Think it's bad or is it just not getting enough vacuum?



It looks like a real pain to swap out



Also, would you happen to have the part munber? It's not showing up in my shop manual...



Thanks!!



Brian

 

[GAmes]

That is the same thing mine did. Double check that you have vacuum at that hose, but it sure sounds like that is the culprit. It is a b---------to get to, just don't get in a hurry. I can't tell you if removing the arm before the mounting screws is the right procedure, sorry. I don't have the PN, but it is in the Dodge parts manuals. Not real expensive.