Checking components and wiring
The blower fan motor power unit is very sensitive to short-circuits and excess current. Do not damage the power unit when taking readings.
Take readings with the power unit connector disconnected when checking the wiring.
Checking the engine cooling fan (FC) motor
Check that the blower fan rotor can rotate freely in the climate control system and that nothing is blocking it. Check by hand whether the blower fan rotor can rotate freely.
Checking the wiring
Check the ground lead between the power unit terminal #A4 and the ground terminal. Check for a short-circuit to supply voltage.
Check the control signal cable between control module terminal #A3 and power unit terminal #A1. Check for an open-circuit. Check for a short-circuit to ground.
Check the diagnostic signal cable between control module terminal #A2 and power unit terminal #A3. Check for a short-circuit to supply voltage.
If the battery voltage has been interrupted, the blower fan speed must be calibrated. First turn the blower fan speed control to maximum speed and then to minimum speed.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box
- To access or replace the control module, see Comfort panel (including climate control module, CCM), replacing
- To access or replace the power unit, see Blower fan motor / power unit, replacing
- For other values, see Signal description, climate control module (CCM), Connector A
- Continue
Refer to Verification