Ok so it's not my blend doors. Everything I have read says the temp will be different on the two side of the vehicle. Well mine will only blow air thru the defroster or the floor vents. I turned it to ac on my drive home (3 miles) to blow on my face. It just blows thru the defroster randomly switching off to blow by my feet generally when accelerating.
Cruise control works so not a vacuum leak.
1)What model do you have? If you have a Laredo, Special Edition, Columbia, Rocky Mountain, or Freedom Edition you have the single zone climate control. It sounds like the recirc door is broken. Try searching for recirc door and see what you find. The recirc doors from that time were notorious for breaking.
2) Vacuum leak - I have a vacuum leak on my WJ and the cruise works fine but the climate control will shift to defrost under load. Likely a check valve that I have not hunted down and replaced.
04 Columbia Ed 4.7 HO/QTII/SSD107/UC/Bilstein 4600/RB4/Moabs/Cooper Discoverer AT3's/PML trans pan
Had the same issue, turned out to be a cracked vacuum line under the battery tray. It was the short tube that went from the plunger to a tee, only about 5 inches long. However, look along the whole run of lines that feed from there to the rear of the engine, leading to the intake manifold. It did affect my cruise, once i got the line replaced, air out of all vents and a working cruise control
2002 Laredo single zone sorry i screwed up not adding that part. ok looks like vacum leak first then recirc doors is the way to go. i have a couple days off coming up finally so i will let you know what i find.