Throttle Body Fuel Injection System

Fig. 003 CHART C-10:

Fig. 004 WIRING DIAGRAM CHART C-10:

CHART C-10

A/C CLUTCH CONTROL

FUEL INJECTION (TBI)
Circuit Description: When an A/C Mode is selected on the A/C control switch, ignition voltage is supplied to the compressor low pressure switch. If there is sufficient A/C refrigerant charge, the low pressure switch will be closed and complete the CKT to the closed high pressure cut-off switch and to CKTs 366 and 604. The voltage on CKT 604 to the ECM is shown be the "Scan" tool as A/C request "ON" (voltage present), "OFF" (no voltage). When a request for A/C is seen by the ECM, the ECM will ground CKT 459 and engage the A/C compressor clutch. A "Scan" tool will show the grounding, or CKT 459 as A/C clutch "ON". If voltage is seen by the ECM on CKT 366 the cooling fan will be turned on.

Diagnostic Aids:
Both pressure switches are located at the rear of the A/C compressor. The low pressure switch is identified by a blue insert and the high pressure switch by a red insert on the connector.