Test Step 5. Check the A/C Compressor Clutch Switch

202

TM 9-2320-312-24-2

Troubleshooting Section

b. Connect a multimeter and measure the

Result 3 Diagnostic Code 110-03 or 110-04 is

resistance between the two terminals of

logged or active.

the A/C compressor clutch switch. The A/C

compressor clutch must be engaged in order

Results:

to check the resistance.

Result 1 Proceed to Test Step 5.

c. The resistance should measure 10 Ohms or

Result 2 The cooling fan is ON because of a

less.

high coolant temperature.

C. If the A/C compressor clutch switch is connected

to P1:62 (Input #12), use the following steps to

Repair: Perform the following diagnostic

check the switch circuit.

procedure: Troubleshooting, "110-11 Very High

Coolant Temperature"

a. Disconnect the wire at terminal P1:62 (Input

#12).

STOP.

Result 3 The cooling fan is ON because of a

b. Connect a voltage test lamp between the wire

that was removed from terminal P1:62 and

coolant temperature sensor fault.

terminal 67 (- Battery).

Repair: Perform the following diagnostic

c. Turn the keyswitch to the ON position. The A/C

procedure: Troubleshooting, "Engine Temperature

compressor clutch must be engaged in order

Sensor Open or Short Circuit - Test"

to check the A/C compressor clutch switch.

STOP.

d. The test lamp should illuminate when the A/C

Test Step 5. Check the A/C Compressor

compressor clutch is engaged.

Clutch Switch.

Expected Result:

The circuit behaved in the manner that was

described in the instructions above.

Results:

Yes The A/C compressor clutch switch and the

wiring are electrically OK. Proceed to Test Step 6.

Repair: Replace the A/C compressor clutch

switch and/or the related wiring.

Verify that the repair eliminates the problem.

STOP.

Test Step 6. Use the Electronic

Service Tool to Check Inlet Manifold

Air Temperature and the Coolant

g00841499

Illustration 62

Temperature.

Pin locations on P1 connector

A. Connect the electronic service tool to the cab

A. Turn the ignition key switch to the OFF position.

data link connector.

B. If the A/C compressor clutch switch is connected

B. Turn the ignition key switch to the ON position.

to P1:41 Input #11, use the following steps to

check the switch circuit.

a. Disconnect the wires at terminals P1:41 and

P1:5.