Fanspeed Medium

Fanspeed Medium

(FANMED) A/CCM Pin 14 ref Pin 6

This signal is generated from the fanspeed control switch. Switch at Low, pin 14 should read 0.6 volts. Switch at Off, L, H or D positions, pin 14 should read 3.6 ±0.8 volts.

Five Volt Supply

(FIVEV) A/CCM Pin 43 ref Pin 6

This 5 volt rail provides the power supply for all the sensors and the feedback potentiometers. Any variation in this signal would totally upset the balance of the whole system.

Flap Servo Drive Signals

The servo drive signals control the position of the upper and lower flaps. The drive signals work in pairs, two for the upper and two for the lower flaps.

Lower Servo Forward Drive

(FORSERL) A/CCM Pin 37 ref Pin 6

Upper Servo Forward Drive

(FORSERU) A/CCM Pin 40 ref Pin 6

Lower Servo Reverse Drive

(REVSERL) A/CCM Pin 41 ref Pin 6

Upper Servo Reverse Drive

(REVSERU) A/CCM Pin 42 ref Pin 6

When the flaps are stationary, all signals will be at 0.6 volts approximately. When the flap(s) is being driven, the drive line(s) will rise to approximately 6 volts. As the flap approaches its final position, the drive signal will be pulsed to nudge the flap to the exact position required.

Note: If a drive signal rises to above 8.5 volts and the servo motor does not operate, suspect an open circuit within the servo.

Ground Voltage

(GND10) A/CCM Pin 10 ref Pin 6

This is the ground supply from the A/CCM to the in-car sensor and should read below 10 millivolts. Failure of this line will cause the in-car sensor to believe the vehicle temperature to be at maximum all the time, thus forcing the system into permanent cooling. Under these circumstances, pin 4 (in-car sensor output) will be approximately 5 volts.