A/C - Switch Revised

90jaguar03

SECTION: 86
WATER TEMPERATURE SWITCH No: 71


Model: 1990 MY SEDANS Date: APRIL, 1990

KEYPOINTS: REVISED SWITCH
Beginning with VIN 594576 (1990 M.Y.), the air conditioning/ heater water temperature switch has been revised in conjunction with electronic control module circuitry changes.

SWITCH OPERATION:

^ Beginning with the above VIN, the operation of the switch has been changed from normally open when the coolant temperature is below 30~C, to normally closed.

^ When the coolant is below 30~C, the switch is closed, supplying a ground to the ECU. This inhibits premature operation of the interior fans, preventing cold air from being blown into the car.

^ When the coolant is above 30~C, the switch will open allowing the fans to operate normally.


NOTE: The revised temperature switch (JLM 2121) and new electronic control module (DBC 4309) are not interchangeable with the previous parts.


^ With the new system, if the temperature switch or the harness become open circuit, the fans will continue to operate even if the temperature is below 30~C.