Assuming that by "high," "low," and "medium" you are referring to HVAC blower fan speed and that this happens with heat as well as with AC:
Replace the blower resistor. It's no good.
Try replace the resistor. It's locate pass.side under dash by fan blower with one plug and two bolts.
There are various sizes and ratings used. Replace with what you take out.
Blower resistor pack broken?
The obvious answer is the one the Jeep sells at its dealerships parts department.
Short
on the dash board
The bleeding sequence is back right,back left,front right,front left works on the later 98's to 2004 jeep grand cherokees
10w30 a synthetic oil works, just not quaker state or mobile one.
Press and hold the reset button about 3 seconds.it gonna be appear how many miles you need... it works..
If you have no heat in your 02 grand Cherokee limited blower works heater lines are hot good circulation just no heat comes out?Maybe blocked heater core. Also check thermostat.Your problem is with the blend doors in the GC. Check the HeaterTreater eBay listings for diagnostic information and a fix.
I talked to one of my friends that works at a car audio shop. So try contacting someplace like that www.installdr.com
chk the ground wire on the harness to the fuel pump...........