PULLER A 7F9540 - Caterpillar

Illustration 1 g02889197
Air conditioner clutch solenoid circuitThis diagnostic code indicates the brake ECM has determined that the air conditioner clutch solenoid voltage is below normal. Possible causes of this diagnostic code are:
Solenoid failure
Harness shorted
Diode failure
ECM failureNote: The following test procedure may create other diagnostic codes. Ignore these codes, correct the original code, then clear these created codes. Ensure that the CID 2671 FMI 04 is active before performing this procedure.Note: Use a calibrated digital multimeter that has a diode test function for this procedure.Test Step 1. CHECK THE DIODE
Turn off the keyswitch and the disconnect switch.
Remove the diode from the harness.
Place the red probe in the red terminal (positive terminal) of the multimeter.
Place the black probe in the black terminal (negative terminal) of the multimeter.
Connect the red probe of the meter to pin 2 of the arc suppressor diode.
Connect the black probe of the meter to pin 1 of the arc suppressor diode.
Turn on the disconnect switch and the keyswitch.
Observe the multimeter readout. The readout will be between 0.5 VDC and 1.0 VDC.
Reverse the order of the probes at the connectors.
Observe the multimeter readout. Expected Result:The meter readout is between 0.5 VDC and 1.0 VDC.Results:
OK - The meter readout is between 0.5 VDC and 1.0 VDC. Repair: Turn off the keyswitch and the disconnect switch.Reconnect the diode to the harness. Proceed to Test Step 2.
NOT OK - The meter readout is not between 0.5 VDC and 1.0 VDC. The diode has failed. Repair: Replace the diode.STOPTest Step 2. CHECK THE RESISTANCE OF THE A/C CLUTCH SOLENOID
Remove the A/C Clutch solenoid from the harness.
Use the multimeter to measure the resistance across the solenoid terminals.
Reverse the multimeter leads.
Measure the resistance across the solenoid terminals.Expected Result:The resistance is between 4 and 16 ohms.Results:
OK - The resistance is between 4 and 16 ohms. Proceed to Test Step 3.
NOT OK - The resistance is not between 4 and 16 ohms. The solenoid has failed.Repair: Replace the solenoid. STOPTest Step 3. CHECK THE SOLENOID CIRCUIT FOR A SHORT The keyswitch and the disconnect switch remain off.The solenoid remains disconnected from the harness.
Disconnect the harness from the brake ECM.
At the harness connector for the brake ECM, measure the resistance from contact J2-10 (wire C510-WH) to all contacts used in the harness connectors for the brake ECM.
At the harness for the AC Clutch relay, measure the resistance from contact C15 (wire E554-PK) to all contacts used in the harness connectors for the brake ECM.Expected Result:Each resistance is greater than 5000 ohms.Results:
OK - Each resistance is greater than 5000 ohms. Proceed to test step 4.
NOT OK - A resistance is less than 5000 ohms. There is a short between contact J2-10 (wire C510-WH) and the circuit with low resistance. The short can also exist between contact C15 of the AC clutch relay and the circuit with low resistance. Repair: Repair or replace the harness.STOPTest Step 4. CHECK THE DIAGNOSTIC CODE
Inspect the harness connectors. Clean the contacts of the harness connectors. Check the wire insulation for damage caused by