I have a 2000 Grand Cherokee. It has the automatic climate control. When I try to use AC/heater, everything works but no air comes from vents. The compressor clutch comes on and you can feel cooler air coming from the vents from convection but no blower motor. It started 2 weeks ago and did it twice - both times after stopping car and restarting the blower motor did work.

There's a two-wire plug that connects to the blower motor. Both have 12 volts on them when I test them. THere's a larger grounding strap that looks like it provides all grounding for the motor. I stretch a hot wire from the battery and touch it to each of the two contacts on the blower motor and get no movement from the blower.

Is it safe to assume the blower motor is bad or do I need to perform more testing? Posssibly in the resistor packs? If so, what testing specifically?

Thanks in advance!

Robert

 

just replace the blower, if its not the problem just return it

 

Hey Robert, Welcome to CF. Read this, it should help. http://www.wjjeeps.com/blower_motor.htm

 

Thanks both of you. Here's where I stand.

1. Blower motor does work - either must have had a poor hot or ground when I tried to manually run it in the car. I removed it, it runs well.

2. Resistor module. Was heated and had deformation of the plug (unable to remove the plug) as shown in the link you posted. I ended up replacing the wiring harness and the wiring module as it had deformation and discoloration on the circuit board as well as that burnt electrical smell.

When I cut the three wires going to the reisistor module I got a quick spark - I cut them all at once. The ignition was off at the time. I read on the link posted above that some models had ignition switch problems that allowed the resistor module to be powered even when the ignition was off.

My problem now is that I get no power to the resistor module. I have checked all fuses inside the car (pulled all of them, viewed and reseated). I have checked the fuses and fusable links in the engine compartment (the power dist module by the battery).

What am I missing? I'm sure when I cut the wires and got the quick spark I ruined a fuse or possibly the blower relay? Where is that located?

****** UPDATE ******
Pulled every fuse in the PDC and the fuse panel inside - two more times. Now it's working. My confidence level is low that it will continue to do so.

Thanks for the help - I do appreciate it!

 

The Blower motor and controller are fused by Fuse 1 (40A) located in the Power Distribution Centre under the hood (bonnet).

Take care, many circuits are not switched by the ignition (as you have discovered) - unless you have evidence to the contrary, assume circuits are powered.