Defrost Solenoid

Defrost Solenoid

(DEFSOL) A/CCM Pin 11 ref Pin 6

The defrost solenoid controls the operation of the screen vents. When the solenoid is energised, the screen vents will be held closed by the vacuum created. To open the vents the solenoid is de-energised.

The solenoid is energised when a ground supply is provided to pin 11. The solenoid is de-energised when the ground supply is removed, at which point 10+ volts can be read at pin 11.

Temperature Differential

(DIFF) A/CCM Pin 28 ref Pin 6

This sets the differential between the position of the upper and lower flaps. With minimum differential selected, pin 28 should read between 0 and 100 millivolts. The voltage at pin 28 will rise smoothly as the differential is increased, up to a maximum of 2.885 volts.

Evaporator Sensor

(EVSEN) A/CCM Pin 5 ref Pin 6

This sensor monitors the temperature of the evaporator matrix, the output is used to trigger the compressor circuit via the A/CCM pin 20. Operating conditions are 2.732 volts at 0 degrees Celsius ±0.01 volts for every degree Celsius above or below zero.

Fanspeed Defrost

(FANDEF) A/CCM Pin 27 ref Pin 6

This signal is normally held at 3.6 ±0.8 volts by the control module. When Defrost is selected from the control panel, the line is pulled down to 0.6 volts or below. This will cause the defrost flaps to open by applying system voltage (approx 11 volts) to pin 11. In addition, both fans will go to full speed i.e. high speed fan relay energised .

Fanspeed High

(FANHIG) A/CCM Pin 15 ref Pin 6

This signal is generated from the fan speed control switch.

Switch at High, pin 15 should read 0.6 volts.

Switch at Off, L, M or D positions, pin 15 should read 3.6 ±0.8 volts.

Fanspeed Low

(FANLOW) A/CCM Pin 13 ref Pin 6

This signal is generated from the fanspeed control switch.

Switch at Low, pin 13 should read 0.6 volts.

Switch at Off, M, H or D positions, pin 13 should read 3.6 ±0.8 volts.