Grand Cherokee 2WD V8-5.2L VIN Y (1998)
Blower Motor Switch: Testing and Inspection
Heater-A/C Blower Switch Test
WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO AIRBAGS SYSTEMS BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
1. Check for battery voltage at the fuse in the Power Distribution Center (PDC). If OK, go to Step 2. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
2. Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Remove the heater-A/C control from the instrument
panel. Check for continuity between the ground circuit cavity of the heater-A/C control wire harness connector and a good ground. There should
be continuity If OK, go to Step 3. If not OK, repair the open circuit to ground as required.
3. With the heater-A/C control wire harness connector unplugged, place the heater-A/C mode control switch knob in any position except the Off
position. Check for continuity between the ground circuit terminal and each of the blower motor driver circuit terminals of the heater-A/C control
as you move the blower motor switch knob to each of the four speed positions. There should be continuity at each driver circuit terminal in only
one blower motor switch speed position. If OK, test and repair the blower driver circuits between the heater-A/C control connector and the blower
motor resistor as required. If not OK, replace the faulty heater-A/C control unit.
