96liftedXJ

So now that its winter my jeep always likes to have problems with the heat every winter. This winter im having a problem with it only working on high. And if i have the vent on the air comes and goes. When it goes it moves it to defrost but my switch is still on vent. So im not to sure what it is. I have heard that there is a electronic control thing under the passenger side dash. But i havent really had time to mess with it. Can anyone help me out here? Its been pretty cold here in ohio and it sucks when your heat only works on high and doesnt blow out the vents all the time. So any kind of input on this would be helpful. Thanks.

dans01classic

check this thread out, might help

https://www.cherokeeforum.com/f2/how...eat-get-68921/

dirtyXJgirl

at least you have heat sometimes. haha.
it has been like 14 in the mornings and i look like an eskimo when driving...

96liftedXJ

Yea i just read through that thread. It helped some. I need to get some info on this blower speed controller before i jump into flushing the core or checking for vaccum lines leaking. But thanks for the info. Yea i pretty much look the same. Its pretty cold at first for a little bit. It goes up to just past 210 and then drops down to 180 then i turn the heat on. Most of the time it blows between between hard and slightly. Then it will go away and then come back blowing hard. And sometimes the heat is hot and sometimes it is just warmer. So its got me somewhat. I just need some input to see what it could be more. I think im going to lean more towards the controller and clogged core. But Just need some input. Thanks

FOXxX

Your problem would be first -

Only on high - sounds like your fan motor bearings may be going bad. Summit has new motors for $60 or so. Just replaced mine - wouldnt blow on low setting and had issues on med. Not too hard to replace - pull off the washer fluid box and it is right there. Put some caulk back on the seal when you replace since that is where the infamous leak is that ruins the passenger floor.

Second -
Defrost is the default setting for the AC/Heat vents. The system works on a vacuum and when there is a leak, cut, or broken line then the system reverts back to the default - defrost. Fix the leak and your problem is solved.

ZaKingHunter

If the blower only works on high, replace the blower motor relay. Its located on the passenger side under the dash.

leighsean

Just went through this same problem...the vacuum line from the vacuum storage tank located on the passenger side in the front bumper was brittle and broken. replaced it and wha lah, HEAT! of course this is on my 90 xj so it might be a little different than yours. $5 fix. Good luck, can post some pics if youd like..

96liftedXJ

Yea can you post some pics just that way we are on the same page of the vacuum canister. Alright thanks guys. I will be working on my jeep this weekend and i will check all of those things.