I just bought my first jeep about a month ago and have noticed there is constantly heat coming from my defrost vents. everything is off but still pushing heat out. I have the temp lever set to cool and even if I switch it to vent its still hot. I tried the search function and couldn't find anything. im at a loss to what it is but have not pulled anything apart yet. any help would be great. thanks guys
I can't be sure this is it but I've had this problem on another car and it was because I had no vacuum to the dashboard controller. The dash controller has two things going on, cables that move duct plenum s around and also vacuum that moves things. I would check both. IIRC when I lost vacuum, the default position was defrost.
07-10-2013 09:19 AM
just checked it out for a min when on lunch and the cables seem to be moving freely although the one that hooks up to the metal tab on the pass side front the little metal tab is secured with some sort of pin looks like and it has a fair amount of slop to it. could that be causing it to not fully close the blend door? didn't have a chance to pull the controller and check vac lines but will do that next. also I happened to pull off the cowl vent off the other day to paint it and noticed there was a rag stuffed down in there on the drivers side. I figured wtf is a rag doing in there and pulled it out. wonder if maybe a prev owner did that to block some of the heat.
07-10-2013 09:18 PM
07-11-2013 09:09 AM
Looking at the link in this post, my theory on the vacuum line doesn't seem to hold up. It looks like you'll need to verify whether the cables are moving all the doors as described in this link.
If you need a quick fix, being it's July, you could disconnect the heater hoses from the heater core under the hood and splice them. That will stop the hot air from coming out of the defroster. Of course, it will prevent you from getting any heat from the system, which may become an issue this fall.
07-11-2013 09:48 AM
I always liked the 90's (maybe even current??) Honda way of controlling heat. The cable actually opened a valve on the incoming heater hose. I never liked the idea of a hot heater core inside the car in the summer.
I looks like it would be rather trivial to convert a YJ to something similar.