Part 1 of 2

Chart C-10A Part 1 Of 2:

Wiring Diagram:

CIRCUIT DESCRIPTION:

The A/C relay is ECM controlled to delay A/C clutch engagement 0.4 seconds after A/C is turned "ON". This allows the IAC to adjust engine rpm before the A/C clutch engages. The ECM may also apply the A/C clutch during cranking to prevent A/C slugging and idle flare at stop up. 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.


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


1. Checks operation of A/C cycling switch.

2. Checks to see if the A/C "ON" signal is getting to the ECM through circuit 67. A test light "OFF" at this time indicates circuit 67 is open between the cycling switch and the ECM.

3. Checks for open circuits 66, 257, 750, or A/C control switch.