Forum Discussion

kmb1966's avatar
kmb1966
Explorer
Jul 23, 2018

Dash A/C blows out of defrost when climbing or head wind

My dash a/c blows cold air, but at times when climbing hills/overpasses or traveling in a head wind, the air will decrease out of the vents, and blow out of the defrost vents. Upon slowing down, the ...
Class A
akrv's avatar
akrv
Explorer
Jul 23, 2018
Loss of engine vacuum which is normal when the engine is under heavy load. I had the same problem on a class c 2004 chassis. When I had a leak the in the heating system it would only blow air out defroster. I had a broken vac line in the engine compartment that a pack rat chewed on.

About Motorhome Group

38,705 PostsLatest Activity: Jan 14, 2025