My 2001 Dodge Ram 1500 5.9L, air conditioning goes from vents to defrost and the on 2001 Dodge Ram 1500

My 2001 Dodge Ram 1500 5.9L, air conditioning goes from vents to defrost and then back to vents when I back off the acceleration. where could the leak be .

by in Laveen, AZ on November 15, 2013
2 answers 2 comments
ANSWER by on November 15, 2013
Look under the hood at the vaccum hose routng diagram and find the hvac hose from the engine then follow it back you will find it.
COMMENT by on November 15, 2013
sounds good. thats what I'm going to do first light. I hope its a quick and unexpensive fix. thanks for your input.
ANSWER by on November 16, 2013
The vacuum line that sources the AC controls connects to the passengers side of the intake, just about mid engine. There is a check valve just a few inches from the engine in the line that goes bad.
COMMENT by on November 17, 2013
Okay l have canister purge solenoid. I have a EVAP canister. andy paper canister purge solenoidall these three items are located on the passenger side firewallwhich is a big part of my system.. I don't see a check valve. I did check every vacuum holes every line from the top to the bottom from back bumper to the front bumper no leaks.. I didn't check the check valve to see if it was good or not