Skylark V6-181 3.0L (1986)
Wiring Diagram for Chart C-12A - Coolant Fan Check
CHART C-12A - COOLANT FAN CHECK
Test Description:
Numbers below refer to circled numbers on the diagnostic chart.
1.
Grounding the diagnostic test terminal should cause the ECM to ground CKT 535 and the fan should run in low speed.
2.
Grounding the temperature switch harness terminal will check CKT 536 and will also check the high side portion of the fan control relay.
3.
Checks CKT 533 between the fan control relay terminal "4" and the motor. If the fan does not operate, CKT 533 is open.
4.
This step checks to see if the temperature switch is grounding and is grounded when the light comes "ON." The switch should close at 108~C
(226~F).
5.
If the vehicle is equipped with A/C, the following steps will check the head pressure switches and related wiring from the switch to the fan control
relay. If poor A/C performance is noted, the A/C pressure switches should be checked by a qualified A/C repair person. The low speed fan should
come "ON" if head pressure exceeds 1036 kPa (150 psi).
