ac and heater problems

[richb2003]

i have a 2003 jgc and the heat and the ac don't work properly. the ac when on goes from cold to warm on its own and the heat goes from hot to cool. does anyone have the same problems or know why this might be happening? also it does not have the dual zone climate control. any help would be appreciated
thanks

[Seacliff]

I am having this same problem with my 1995 Grand Cherokee Limited and have an appointment tomorrow to get it checked out at the local service/dealership. Any hints before I go? I'll re-post after I get a diagnosis -- or better still, a fix! (It's hot out there!)

[richb2003]

good luck at the shop! i hope they can tell you what it is. maybe that will point me in the right direction with mine. thanks again for the reply, hope to hear some good news on whats wrong.

[Seacliff]

At first I figured my climate control system was doing the heat/freeze swing thing mostly in the summer, so I'd had it recharged (and now that I look back at my repair records, it seems I've been doing that once and twice a year for the past couple of years). However, this winter I noticed that the heat, too, was fading in and out on me. And sometimes the control panel where it says the temp youv'e set it to (e.g., 72o) would instead read "Er".

So, the local Jeep delearship took a look this afternoon and have determined that there's a leak in the evaporator coil (suspected that with all the recharging I've had to do), but also that (and I'm quoting here because I don't know cars...) my "heater control has bad actuator."

All told, this is going to cost me $820 to fix, which is certainly not peanuts, but in the hopes that the car will last another couple of seasons or dare I say it, years..., I'm going for it. Again, I am not into my car or fixing it myself, so I have no idea how much and how feasible it is to DIY.

Hope that helps and best of luck with yours!

[RunMonkeyRun]

Can you ask them what the heater control actuator does? I am retty sure my self that I have a very slow leak at the evaportor, but I dont get the same heat and my a/c is now fully charge and I dont get the same cool air i used to.

[tech_ed]

Vacuum...that's what drives the controls, or "motors" for the climate control system. They are everywhere...There's one under the hood that opens and closes the heater core to the hot radiator fluid. This allows radiator fluid that is heated by the engine to enter the heater box where the fan blows air across it to get heat!
when you want cold, the compressor sends compressed freon into the evaporater where it expands and gets cold. Blowing air across this give cold air.
There is a little door that is controled by a vacuum motor that switches between the two. This is actuated by a vacuum motor. Chances are that either this motor is bad, or the vacuum connection to the motor is loose or not there. Either way, if you don't mind spending several hours lying on your back with your head on the floor and your feet up in the air and scratching and cutting the heck out of your hands, you can probably find the offending motor and probably replace it yourself...just not a fun job...your call.
Ed
web/gadget guru

[RunMonkeyRun]

Thanks tech ed I guess I am "scratching and cutting the heck out of my hands" as soon as I ge the time. I don't even get cool with my a/c on and its fully charged thats what pisses me off I mught aswell drive with the windows open with this heat.

[Seacliff]

Seems that is the electronic bit that controls the actual flaps and doors that direct the heat to the windshield, your feet, etc. It also controls where the hot/cold air is pulled from.

Unfortunately, their repair of mine doesn't seem to be "sticking". I picked up the car and it was fine (and blowing deliciously cold air all over the place), but later that afternoon, after it sat outside in a verrrry hot parking lot for a couple of hours, there was only cold air blowing at the passenger feet and nowhere else.

Plus, now when I change my vents from face or windshield to feet, there is a little clunking noise behind the dash (likely the flaps/doors moving).

It is my theory that there is some muck in the big "box" where all that air is flowing and being diverted. I've noticed a thick dark "sludge" on my vents in the car over the years which is fine for a car 10 years old, but I am thinking this stuff is all in that flowing box, too. I think when the car heated up, those doors/flaps expanded just enough to get stuck in the goo.

However, the dealer may have another "theory". I'll know tomorrow when I take it back in AGAIN to be fixed...