Great Lakes 4x4. The largest offroad forum in the Midwest - View Single Post - HVAC switches to defrost under load.
View Single Post
Old August 28th, 2007, 05:02 PM   #1
GreaseMonkey
Senior Member
 
GreaseMonkey's Avatar
 
Join Date: 11-04-05
Location: Madison Heights, MI
Posts: 18,003
iTrader: (22)
Mentioned: 1 Post(s)
Default HVAC switches to defrost under load.

Here's my other issue on my truck ('01 Dodge Ram 4x4).

Say I have the A/C pointing at my face. If I'm on the freeway and give it 3/4 throttle so the load increases on the engine, the vacuum change causes my HVAC to switch to defrost.

I've checked with tech manuals and it is supposedly a common problem says to replace both check valves on the vac lines near the intake manifold.

I pulled both valves and checked them and they hold vacuum. The lines don't seem to have any leaks either.

Any help?
GreaseMonkey is offline   Reply With Quote
 
Page generated in 0.04376 seconds with 20 queries