Cutlass Supreme FWD V6-189 3.1L (1989)
Coolant Fan Does Not Run
1.
With ignition switch in RUN position, ground white/black wire terminal of ALDL connector. If coolant fan runs, problem is ECM related.
2.
If coolant fan does not run, ground dark green/white wire terminal at ECM with a fused jumper. If coolant fan runs, problem is ECM related.
3.
If coolant fan does not run, leave fused jumper connected as in step 2, disconnect coolant fan relay connector and measure voltage from red wire
terminal to ground. If battery voltage is not present, check fusible link E and red wire for open.
4.
If battery voltage is present, leave fused jumper connected as in step 2 and measure voltage from pink/black wire terminal to ground. If battery
voltage is not present, check pink/black wire for open.
5.
If battery voltage is present, leave fused jumper connected as in step 2, disconnect coolant fan relay connector and measure voltage between red
and dark green/white wire terminals. If battery voltage is not present, check dark green/white wire for open.
6.
If battery voltage is present, disconnect primary coolant fan relay connector and connect 20 amp fused jumper between red and black/red wire
terminals. If coolant fan runs, replace coolant fan relay.
7.
If coolant fan does not run, leave fused jumper connected as in step 6, disconnect coolant fan connector and measure voltage between black/red
wire terminal and ground. If battery voltage is not present, check black/red wire for open.
8.
If battery voltage is present, leave fused jumper connected as in step 6, disconnect coolant fan connector and measure voltage between black/red
and black wire terminals.
9.
If battery voltage is not present, check black wire for open.
10.
If battery voltage is present, replace coolant fan.
Coolant Fan Runs Continuously With Engine Coolant Cool & A/C Mode Selector Off
1.
Disconnect coolant fan relay connector and connect test lamp between pink/black and dark green/white wire terminals. If lamp does not illuminate,
replace coolant fan relay.
2.
If lamp illuminates, check dark green/white wire for short to ground. If wire is satisfactory, problem is ECM related.