Rolller

I have recently replaced the heater core and had the condenser coil tested in my 1999 Cherokee Limited. I have everything back together now. The heater works great, no rattles or noise in the unit, the vents adjust from upper to lower, but the vent wont blow cool air and the ac doesnt blow cool air. I am in Michigan right now so the cool vent should produce cool air, right? The ac blows hot air, although it has not been recharged since the heater core replacement, shouldnt it at least blow cool air when selected? My first thought is the blend door. I am really hoping that there is an easier fix that a complete removal of the unit again. Please Help

Thanks

Rolller

Does anyone have any possible suggestions on this issue? I am planning on tearing back into it this afternoon.

Much thanks in advance.

Illuminator

Check the vacuum lines and make sure their connected good, make sure there's nothing blocking the blend doors path.

Rolller

Illuminator,

Thanks for the reply. Yes, I have checked those and everything seems fine. When I change the temp from hot to cold, or visa versa, I can see the post rotating about 100 degrees. This is the post on the motor directly above the passenger floorboard. I think that is the blend door, correct? If so, then the blend door is working, I have plenty of heated vent, but no cool vent or cool ac, both of those still blow hot air. I am really perplexed on this problem. Im thinking about taking it to a repair place just to have it diagnosed but worried they may send me on a while goose chase.

Also wanted to add that I have not recharged the AC yet. I wanted to get this problem fixed first before I wasted more freon in case I had to take it all apart again. I dont know how this could affect not getting cool air from the vents, and I would assume that I would get at least some cool air from the AC event if it wasnt charged, again, Im in Michigan right now.

Rolller

Ok I have removed and installed the dash TWICE now!!!! can not find the problem. The blend motor works, all hoses and lines are connected.

I think I may have pinched the door when I put the HVAC box back together the first time. This time I spayed the pivot points with a little lubricant and made sure that the pivot post was in the correct position. When I put it all back together the problem is still there. I can see the little stud on the motor turn. The splines inside the door shaft and on the motor stud look fine, no signs of being worn down or none broken.

Almost every site that I can find on this issue is about the Grand Cherokee. Very very few sites on just the Cherokee. Grand Cherokee has more digital instruments and dual doors and not in the same location. On my 1999 Cherokee Limited, the door is vertical, positioned between the heater core and the ac coil. The motor is on the bottom of the HVAC box and is just right of the tranny hump on the passenger floorboard. I can not find another website to show this.

Can anyone here help please???

99 Purple XJ

If theres no freon it isnt going to blow cold a/c air

Rolller

Right now in Michigan????? I cant get cool air through the vents. It blows hot air all the time. Even without the AC being charged it should still blow cooler air than the heated air.

00jeepXJ

a large number of auto's use a temp sensor to allow engagement of the a/c system. There is a good chance that your jeep won't allow you to kick the a/c on and test it because of the weather that we are having in this wonderful state... yea 45 yesterday and now 35 with rain and sleet. I would test defrost... if your a/c compressor kicks on then you should be ok for the time being until spring or summer.

XJDC

It is the blend door. Even if there isn't any freon in the ac system, if it is on cold it will bring air in, not through the heater core. I suggest checking again. The blend door is cable controlled. There could be something blocking it or it is not engaging all the way, or maybe mechanically broken. Thorough inspection is probably required. My cable was stuck when I did my heater core and the **** was hard to turn and didn't fully rotate. Took it back apart and the cable was snagged. Hope this helps.

inghamjon

Hi, I don't think that the blend doors are cabled controlled. I have the same problem in my 2000 Jeep and the heater control **** has no cable attached to it just electrical wires. I also have no cold air. It is as if the temp control **** is stuck on hot.

My XJ Her TJ

Have you tried moving the blend door by hand with the motor removed?
I'm having this heat all the time and do not see my blend door move much when going from hot to cold. I'm going to remove the motor and see if I can turn it to cold manually.