Convict1997
Well-Known Member
- Joined
- January 2, 2003
- Messages
- 155
- Reaction score
- 0
- City, State
- Concord, NC
- Year, Model & Trim Level
- 1996 2wd XLT 4.0 OHV auto
In my 2002, when driving up a hill, the a/c will change from the vents to the defrost. Once I get up the hill, it will switch back to the vents. Sounds like some kind of vacuum issue. It only does it if I stay off the gas and make the truck stay in o/d. If I use the button to turn o/d off or give it enough gas to down shift, then it will stay on the vents. I've also noticed a hissing sound coming from under the dash when I initially press the gas. Could these two be related? Maybe a leaking vacuum reservoir, or something?