Engine - Coolant Temperature Sensor/Switch: Service and Repair

*** UPDATED BY TSB ENG006, DATED APRIL 1989

Fig. 1 Air Conditioning And Cooling Fan (Engine).:

COOLING FAN CIRCUIT (WITHOUT RELAY)





MODIFYING CIRCUIT TO INCLUDE RELAY

The radiator cooling fan control circuit has been changed from a direct thermo-switch activated type to a thermo-switch with relay type. The relay type circuit went into production on 12-5-88 and is now available as a service kit for vehicles produced prior to that date.





Service Kit Installation Procedure

1. Note the customers preset radio selections.
2. Disconnect the negative battery cable.
3. Disconnect the radiator cooling fan motor leads from the main harness and the thermo-switch.





4. If the thermo-switch must be replaced, drain the coolant from the radiator. Remove the old thermo-switch and install a new one and torque to 14-18 lb.ft. Refill cooling system with coolant.

5. Install the relay provided with the service kit on the right inner fender using the radiator reservoir mounting bolt.








6. Extension Harness Connections
a. Connect the female connector with the long leads (1) to the thermo-switch.

b. Install the short wire loop connector (2) into the connector on the thermo-switch side of the radiator fan motor.








c. Connect the square connector (3) to the power relay previously installed on the right inner fender.

d. Connect the female connector with the short leads (4) to the connector on the main harness side of the radiator fan motor.





e. Connect the male connector (5) to the main harness.

7. Reconnect the negative cable to the battery and reset the radio presets and the vehicle clock. Test drive the vehicle and confirm the proper operation of the cooling fan.

Production Change Effective

Date VIN

12-5-88 LA32J8KU326310

LD11J4KU307600 LF21J1KU579103