Component Diagnostic Charts/Tests

Chart C-10:

Wiring Diagram For A/C Clutch:

Relay Component Location:

CIRCUIT DESCRIPTION:

With A/C on, alternator voltage is supplied, actuating the A/C power relay, through the low pressure switch, through the high power switch (identified by its red color) to the A/C clutch relay and the compressor. If the A/C system refrigerant level is OK, the low pressure switch will be closed. This completes the circuit through the closed high pressure cut-off switch to circuit 257. Circuit 257 supplies voltage to the A/C control relay and the ECM terminal "B8." The ECM will delay approximately 0.5 seconds, then ground terminal "A4" and circuit 248. This will close the A/C relay and allow current to flow, and circuit 340 to engage the compressor clutch.