Chart C-10A A/C Clutch Control

Fig. 025 - Chart C-10A - A/C Clutch Control.(2 of 2):

Fig. 026 - WIRING DIAGRAM for Chart C-10A A/C Clutch Control. VIN J:

CHART C-10A, A/C CLUTCH CONTROL

ECM control of the A/C clutch improves idle quality and performance by;
a. delaying clutch apply until the idle air rate is increased.
b. releasing clutch when idle speed is too low.
c. releasing clutch at wide open throttle.
d. Smooths cycling of the compressor by providing additional fuel at the instant clutch is applied.
Battery ignition is supplied directly to the A/C relay on CKT 39. When the A/C is turned on voltage is supplied to the A/C relay coil on CKT 459 through the closed cycling switch. This same voltage is supplied as a signal to ECM pin B8 (A-B connector). After a time delay of about 1/2 second the ECM will ground terminal C2 of the C-D connector, CKT 458, and close the A/C relay.
When relay is energized battery voltage from CKT 39 is supplied to the A/C clutch through the relay and CKT 59.