Component Diagnostic Charts/Tests

Fig. 004 - WIRING DIAGRAM for Chart C-10A A/C Clutch Control (1 of 2). VIN 3:

CHART C-10A, A/C CLUTCH CONTROL(1 OF 2)

The A/C clutch control relay is ECM controlled to delay A/C clutch engagement .4 seconds after A/C is turned on. This allows the IAC to adjust engine RPM before the A/C clutch engages. The ECM also causes the relay to disengage the A/C clutch during WOT operation. The A/C clutch control relay is energized when the ECM provides a ground path for CKT 366.

Fig. 003 - Chart C-10A - A/C Clutch Control (1 of 2).:

1. Checks to see if ECM is controlling A/C clutch control relay.
2. Checks operation of A/C cycling switch.
3. Checks for grounded CKT 366 to ECM. At this point the test light should be off.
4. Checks for open circuit on either side of relay coil.

Fig. 004 - WIRING DIAGRAM for Chart C-10A A/C Clutch Control (1 of 2). VIN 3:

CHART C-10B, A/C CLUTCH CONTROL (2 OF 2)

The A/C clutch control relay is ECM controlled to delay A/C clutch engagement .4 seconds after A/C is turned on. This allows the IAC to adjust engine RPM before the A/C clutch engages. The ECM also causes the relay to disengage the A/C clutch during WOT operation. The A/C clutch control relay is energized when the ECM provides a ground path for CKT 366.

Fig. 005 - WIRING DIAGRAM for Chart C-10A A/C Clutch Control (2 of 2). VIN 3:

1. Checks for battery voltage to relay through CKT 67.
2. Substitutes for relay to determine if problem is in relay or in CKT 59, A/C clutch coil, high press. switch, or ground.
3. Checks for open in CKT 67 between cycling switch and A/C fuse, or open CKT 67 to relay.
4. Checks to see that "A/C on" signal is getting to ECM through CKT 67. A test light off at this time indicates CKT 67 is open between the cycling switch and the ECM.