i have a issue with heat that seems to be coming from in between my defrost and the windshield. could i put a manual cutoff in the heater core to stop this? this is on a 89 wrangler. thanks.
If it happens on the highway when going up a hill or overpass, it could be that you are running out of vacuum (because the Jeep is at WOT). What I did was simply buy a $15 vacuum reservoir and stick it under the hood to supply the HVAC system, and I have never had the problem again.
In my case, I kind of overdid it, as I have a reservoir for the HVAC, 2 more for the Cruise Control (which is still acting up, but I think it is more of an electronic issue than a vacuum issue), and one for the brake booster (this is a big one). Only problem I still have is that the cruise control looses power after a while and I have to disengage it. I am still hunting for a vacuum leak, which I am sure I have, but I have been unable to locate (I already replaced most - if not all - of the vacuum lines!).
Felipe
