I have a 1998 Jeep Grand Cherokee Laredo-4 cyl.
So far..I have checked all of the fuses, replaced the switch panel, relay and resistor. I have pulled off the blower and direct connected it to the battery and it runs great.
My delima is..Neither the A/c nor the heater works. :1zhelp:
We have a new baby in the house and 103 degree heat for the next 2 days ..
I am grateful for any help I can get. Thx!

I'm guessing you mean it has a 4.0L 6 cyl, but I doubt it matters in this case. If it is the same as a Cherokee, then the resistor controls the ground, so with the blower on, jumper it to ground just to rule out a defective resistor (probably not, but easy to test.)

If that doesn't work then check for voltage at the blower.

If there is no voltage at the blower, start from the begining and work your way through the system, checking for voltage. Probably fuse, switch then relay.



Good luck,
Dustin