Grand Prix V6-191 3.1L (1989)
Heavy Duty Coolant Fan: Symptom Related Diagnostic Procedures
- Symptoms - With Heavy Duty Cooling
Refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS, for wiring schematics.
Neither Coolant Fan Runs
1.
Turn ignition switch to RUN position, disconnect primary coolant fan relay connector and measure voltage.
2.
If battery voltage is not present, check pink/black wire for open.
3.
If battery voltage is present, proceed to Primary Coolant Fan Does Not Run and Heavy Duty Coolant Fan Does Not Run.
Primary Coolant Fan Does Not Run
1.
With ignition switch in RUN position, ground white/black terminal of ALDL connector. If primary coolant fan runs, problem is ECM related.
2.
If primary coolant fan does not run, turn ignition switch to run position and ground dark green/white terminal at ECM with fused jumper. If
primary coolant fan runs, problem is ECM related.
3.
if primary coolant fan does not run, turn ignition switch to RUN position, leave fused jumper connected as in step 2, disconnect primary coolant
fan relay connector and measure voltage from red wire terminal to ground. If battery voltage is not present, check for open in red wire.
4.
If battery voltage is present, turn ignition switch to RUN position, leave fused jumper connected as in step 2 and measure voltage between red and
dark green/white wire terminals. If battery voltage is not present, check dark green/white wire for open.
5.
If battery voltage is present, disconnect primary coolant fan relay connector and measure voltage from pink/black wire terminal to ground. If
battery voltage is not present, check pink/black 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, check primary coolant fan relay connector terminal contact and, if satisfactory, replace primary coolant fan relay.
7.
If primary coolant fan does not run, leave fused jumper connected as in step 6, disconnect primary coolant fan connector and measure voltage at
black/red wire terminal. If battery voltage is not present, check black/red wire for open.
8.
If battery voltage is present, leave fused jumper in place as in step 6 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, check primary coolant fan connector terminals for cleanness and tightness and, if satisfactory, replace primary coolant
fan.
Heavy Duty Coolant Fan Does Not Run
1.
With ignition switch in RUN position, ground dark blue/white wire terminal at ECM with fused jumper. If coolant fan runs, problem is ECM
related.
2.
If coolant fan does not run, leave fused jumper connected as in step 1, disconnect heavy duty coolant fan relay connector, turn ignition switch to
RUN position and measure voltage from pink/black wire terminal to ground. If battery voltage is not present, check pink/black wire for open.
3.
If battery voltage is present, leave fused jumper connected as in step 1, turn ignition switch to RUN position and measure voltage between
pink/black and dark blue/white wire terminals. If battery voltage is not present, check dark blue/white wire for open.
4.
If battery voltage is present, measure voltage between red wire terminal and ground. If battery voltage is not present, check red wire for open.
5.
If battery voltage is present, disconnect heavy duty coolant fan relay connector and connect 20 amp fused jumper between red and black/red wire
terminals.
6.
If coolant fan does not run, check black/red wire for open.
7.
If coolant fan runs, check high speed coolant fan relay connector terminal contact and, if satisfactory, replace high speed coolant fan relay.
Primary Coolant Fan Runs Continuously With Engine Coolant Cool & A/C Mode Selector Off
1.
Disconnect primary coolant fan relay connector, turn ignition switch to RUN position and connect test lamp between pink/black and dark
green/white wire terminals.
2.
If lamp does not illuminate, replace primary coolant fan relay.
3.
If lamp illuminates, check dark green/white wire for short to ground. If wire is satisfactory, problem is ECM related.
Heavy Duty Coolant Fan Runs Continuously With Engine Coolant Cool & A/C Mode Selector Off
1.
Disconnect heavy duty coolant fan relay connector, turn ignition switch to RUN position and connect test lamp between pink/black and dark
blue/white terminals.
2.
If lamp does not illuminate, replace heavy duty coolant fan relay.
3.
If lamp illuminates, check dark green/white wire for short to ground. If wire is satisfactory, problem is ECM related.
- Symptoms - Without Heavy Duty Cooling
Refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS, for wiring schematics.
