for some reason my Heat and Air only come out of the defrost and floor vents when I deferred to the Dashboard Vents it remains on either the floor or defrost Vents , you Can hear when you turn the switch between – Dashboard ,defrost ,air-conditioning the switch is working you can hear the clutch come on when I turn on the air but it still remains defrost and heat vents only,
another thing is the engine light came on Took it to the shop they said I have an air leak could be a gas cap they did a smoke test didn't see nothing , changed gas cap still have the engine light on , forgot to tell you about my Vent problem I wonder if it has something to do with a vacuum leak to control for the vent doors I don't know squat to what To look for , but a little help in guidance would be greatly appreciated
thank you very much
Zorba

 

What is the vehicle?

 

Sorry it's a 2001 Dodge Ram van 1500 5.2

 

This is a common problem with the trucks. It's a broken vac line going to the hvac control or a bad check valve.

 

Take a look on the passenger side of the intake manifold for a vacuum hose. It should go to a check valve and then to the vacuum reservoir behind the passenger head light. Any break in this vacuum line will keep the dash vents from coming on.

 

Thanks I'll take a look at it hopefully this weekend and get back to you
Thank you very much

 

OK I finally got to it but I had to take it to my mechanic because my radiator went out and some other things had to be addressed ,so he took he did a smoke test and they found that the heaven control and the Chechen valve or holding and he got my vents working forgot what he did to get it working but he did find two canisters under the driver side seat that appears to have smoke coming out , it's still up in the air and he didn't want to take them out so we call Chrysler Dodge and they said that one of the canisters were discontinued still don't know which canisters is discontinued , like to know if you know what canisters he's talking about and if you can bypass them or one or what can I do if I can't find one
Again thanks for all your help any help would be appreciative
Zorba

 

OK it's evaporator canisters one is round and one is square and discontinued is there any place you know of ? website,dealer that I can pick them up that might still have them ?

 

Are the canisters cracked and leaking? Or is it that the rubber lines connected at the top of the canisters are cracked and rotting over the years?
Had a similar issue a while back and i had found the rubber lines were loose as they didn't have any clamps ( just pushed on the nipple) so not secure anymore as they must have once been.

If I recall it right the canisters are mounted on a bracket together and only 2 bolts hold it to the frame. Wouldn't hurt to drop it and have a look at those lines and connections and repair bad hose rather than buying new canisters...

 

Thanks going to look into it today he just didn't want to take it down just in case the canisters are cracked and we can't find around because its been discontinued but if the lines are OK what can we do about the canisters can we substitute the round one with another square one? bypass it or something ( why would' they just discontinue one canister.) there's not a dealer in the country that has that round canister , any suggestions May have to go to the boneyard , Thanks again ,I'll keep informed and again I love this Forum , you all our great!