Somerset V6-181 3.0L (1986)
8.
If the test light is "OFF" after disconnecting, the ECM is shorted internally. Before replacing the ECM be sure and check the resistance value of low
speed side of the fan control relay. Replace if resistance is less than 20 ohms. Also, be sure that CKT 535 is not shorted to B+, and check the
resistance of the canister purge solenoid, and replace if under 20 ohms.
Chart C-12B - Coolant Fan - No Low Speed Fan
CHART C-12C - COOLANT FAN - NO LOW SPEED FAN (CONTINUED FROM CHART C-12A)
Test Description:
Numbers below refer to circled numbers on the diagnostic chart.
9.
Checks for B+ at relay harness connector.
10. Jumpering terminals "1" to "4" bypasses the relay which should cause the fan to run if fan motor and wiring to the motor are good.
11. Grounding the "test" terminal should cause the ECM to ground CKT 535. At this point, the test light should light if the ECM is good and CKT 535
isn't open.
12. This checks for battery + and ground to the fan motor. A test light "ON" at this point indicates a faulty fan motor connection or motor.
