Part 2 of 2

Chart C-10 Part 2 Of 2:

A/C Control Circuit.:

CIRCUIT DESCRIPTION:

The A/C relay is ECM controlled to delay A/C clutch engagement 0.3 seconds after A/C is turned "ON." This allows the IAC to adjust engine speed before the A/C clutch engages. The ECM also causes the relay to disengage the A/C clutch during WOT operation. The A/C relay is energized when the ECM provides a ground path for CKT 366.

NOTE: Because of all the possible color code combinations used on electrical wiring diagrams, always refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC WIRING DIAGRAMS/ECM CONNECTOR IDENTIFICATION for correct color code identification of circuit.

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

3. Test light "ON" verifies the integrity of CKT 366, 639, and QDM "B" in the ECM.

4. Test light "ON" verifies the integrity of CKT 639 to terminal "A" of the A/C relay.

5. Bypasses the relay to determine whether the relay or the compressor clutch or clutch wiring is faulty.