2002 grand cherokee limited with auto climate control. no heating problems until today...now no air movement at all. the heater blower will not turn on even after moving switch from auto to low/high. had blender door fixed a couple years ago. thoughts?

You will have to check the flap operating controls behind the centre consol as anything could be wrong from a vacumn pipe to a operating mechanism ,even the computer controlling the climatic control .

Check where the wires go into the blower housing. There is usually what appears to be a small plate held by 1 or 2 screws that the wires plug into. This is the speed control resistor. If it's going bad, it will cause the problem you describe.

sounds like it could be the motor ..if so nasty job .. you can download complete manuals on the internet for free ..then you can take it from there wether or not you wish to tackle the job yourself .. good luck

I had this problem on a 99 grand cherokee limited, It was the heater blend doors and if you have dual climate control one side usually goes out before the other. These blend doors are located behind the glove box unaccessible inside the HVAC shell.
(http://www.wjjeeps.com/hvac_sub_assembly.htm) Motor failures for this HVAC sub assemblies is also something to look for although much less common.
My local dealership estimated $$$$$$$$$950.00 because they have to remove the entire dash so I looked around for something else.
http://cgi.ebay.com/ebaymotors/Blen-Dor-Jeep-Grand-Cherokee-Blend-Door-Heater-Repair_W0QQcmdZViewItemQQhashZitem3eef1e1cd6QQitemZ270299700438QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

I used something similar to this and now have heat that is controlled solely by the knob nearest the driver. It wasn't very difficult just kind of a tight squeeze.
Hope this helps
GOOD LUCK

a common problem ( mine did it too ) is the blower control relay, under the glove box and behind. it requires taking out the glove box, buying a relay and installing it. unfortunately, the relay often cooks the incoming wire harness, requiring cutting those wires and putting cut wires into new harness. check with www.wjjeeps.com for details.

I have the same problem... If you have the auto climate control like I do there is a resistor at the bottom of the HVAC assembly right where the passengers foot would go. Be careful playing with these wires but you can wiggle them around and sometimes it worksish. But I've seen jeeps that the entire inside has burnt out because of that wiring. It is hard to find this part without going to the dealership stores say they can order it and then call later and say they cant. But you have to replace both the wiring and the heater resistor which will be a good days worth of work.

It could be a poor seal but I've never seen it. What you could have is a fresh air door not closing properly. Fresh air door/recirculation same thing.

look for Main A/C relay, look for fuses, or go to a/c shop and have gas check out, perhaps leaks, perhaps evaporator, perhaps condenser, but start for relay box on front passengers side, or fuses on same side

generally this is caused by a "blend door " motor (actually a vacuum control) not working. I don't have a diagram on this but if you watch the motors mounted to the heater box under the dash, and operate the control, you likely will find one not moving (check all positions including a/c)

I believe its the adjuster doors. It is electonically turned from cold to hot and doors are probably seized. Its a very expensive fix, cost me over 1000.

good luck, its the first of many heater problems.