I have a 97 4x4 318 auto. When I accelerate my heater vents change from the settingI have it on. Then when the RPMs comeback down itgoes to the correct setting. I've looked for a vacuum leak but can't find one. It also went through a fazeof revving when I started it, to about 1200 rpm then down. More thanusual.Any reason for thevacuum problem.

 

There should be check valves inhe vacuum lines going in to your bulkhead, these usually go bad causing the problem you are describing.

Will

 

Thank you

 

mine does that too, Iv just delt with it figguring it was a ram design flaw.

 

I installed the check valves and it seems to have fixed my problem...so far

TSB:
http://dodgeram.info/tsb/1996/24-01-96a.htm

Brad