Chart C-10 A/C Clutch Control, 1984 VIN J (1.8L) Turbo

Fig. 012 - WIRING DIAGRAM for Chart C-10 A/C Clutch Control. VIN J:

CHART C-10, 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 C-2 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.

Fig. 011 - Chart C-10 - A/C Clutch Control (1 of 2):

1. Solenoids and relays are turned "ON" or "OFF" by the ECM internal electronic switches called "drivers". Each driver is part of a group of four called "Quad-Drivers". Failure of one can damage any other driver within the set.

Solenoid and relay coil resistance must measure more than 20 ohms. Less resistance will cause early failure of the ECM "DRIVER". Using an ohmmeter, check the solenoid and relay coil resistance of the following before installing a replacement ECM.

- A/C clutch control relay
- Fan control relay
- TCC solenoid

Fig. 012 - WIRING DIAGRAM for Chart C-10 A/C Clutch Control. VIN J:

Fig. 013 - WIRING DIAGRAM for Chart C-10 A/C Clutch Control.(2 of 2) 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.