Hi,

I just puchased a Roadtrek 170 ( Dodge Ram Van 2500 ) based van camper, so I am new to Dodge.

I was wondering if anyone has had any experience with faulty HVAC controls? I am not able to use the lever on the right at all ( picture attached ) that controls where the air is supposed to go. It all blows onto the windshield in AC FORWARD mode only, all the other selector position yield no air coming out at all. Any idea of what could fix this strange phenomenon? I checked all the connections, they look fine.

Thank you for your help in advance,

Sergio

 

No vacuum to the selector switch will cause this to happen.

 

What year van? If you've been searching on this problem you've likely found it isn't so much your control as ( it is either a check valve or vacuum line(s)... ) or both.

On mine, with the motor cover off, look on the passenger side of the intake and you'll see a vacuum port with a couple vac lines, and likely a check valve, then split off by a connector. Follow those lines and elbows... check them good. It seems some year vans the number of lines seem to run slightly different but lead to about center of the firewall. One of them goes in to your hvac control.

I have 3 lines into /out of the firewall. One coming out goes directly to the water valve that's attached to the heater core line in (it's white while the others are black in color) , controls hot water flow when you use max A/C.
Another comes out and is routed around the passenger side to just underneath the passenger side headlight to a vacuum reservoir ball and splits off from there to the driverside under the battery and cruise control.
The third is the line in supply from the check valve and intake nipple

All these lines and elbows are suspect for being cracked and or leaking. back a short while ago I had been messing around with these lines and bent the" white" line to the water valve I had mentioned above and it just flat out broke in two with such slight effort... I continued bending the line until it would not break anymore and replaced the broken section. Now the water control works again on Max A/C

My vents switch temporarily when driving under a load (like uphill) but switch back to where I had it set once I let off the pedal. Still haven't found exactly where other leaks are either, but still suspect the plenum gasket has some role in the loss of vacuum

 

It's a 1999 with 264, 000 miles !! Thanks for the replies. I was suspecting it could be the vacuum lines :/ I am going on a road-trip this weekend, but I will update when I find the culprit. The good news is that my fridge works just fine, and it is stocked full of Stouts and IPAs

 

There's a vacuum line that comes off the passenger side of the intake. It then runs to the vacuum reservoir under the passenger headlight. From there it runs back through the firewall to the HVAC controls. Inspect this line for breaks or cracks.

 

Thanks, I will inspect and report back.