Engine cooling fans dont work - 1995 Oldsmobile Cutlass Ciera

They switch on when the water temp.reaches a certain heat.

3liter 6cyl? (5 or 6 engines used, 2.2L up to 3.8)
in all cases (engine rad cooling fan) (seems not)
clutch fan failure? (if old mech. type fan) replace it.
if electric fan?

1. bad control sensor.
2. bad controller
3. bad fan relay
4. bad fan
5. bad wire/ connections between them.
6. 
   

what we do is get it hot and see if fan works at the FSM stated trip temperature. (225F is a guess, ) alldata.com has this number too.
if the fan is dead, we check voltage the fan, 12v ? fan is dead.
0 volts? yes, then control is bad.
the work backwards from here, finding true cause. easy huh?
any cheap voltmeter made works .

the ECT is for the engine. EFI system. TBI?
but the Fsm states.
All models equipped with electric cooling fans use this sensor to control the cooling (radiator) fan operation.

i dont have the wiring set for this car.
try alldata.com and use that for fan wiring ,etc.

if engine at long stand still,the engine temperature will rise about 190 degrees the cooling fan suppose to automaticaly turn on when coolant temperature sensor get hot it cause its resistance decrease causing pcm to send power to coolant fan relays and cooling fans, when you turn on AC the cooling fans suppose to turn on to cool down AC CONDENSOR, IF NOT AC WONT WORK COOLING FAN COOLS DOWN REFRIGERANT SO IT CAN RECYCLE THROUGH THE SYSTEM AGAIN.your cooling is suppose to turn on when engine at a sit still if vechicle not moving as coolant temperature rises at a set point the cooling fans will turn on cool down engine.cooling fans dont turn on when you first cold stsrt vechicle unless you have AC SWITCH ON.if cooling fans dont turn on when vechicle at a long stand still or moving along slow traffic.if coolant temperature sensor been replaced and fuses and relays okay have dealership check see if pcm driver circuit working faulty pcm will cause cooling fans not to turn on.

Most electric cooling fans are noisy. They move large volumes of air to cool the engine. You will hear this noise most predominately when the fan spools up when you are stopped at a traffic light. As long as it is working and cooling the engine I wouldn't worry about it.

COOLING FANS DONT TURN COULD BE FAULTY FAN RELAY.FAULTY PCM AND FAULTY COOLANT TEMPERATURE SENSOR.CODE SCAN FOR FAULTY PCM CODE AND A FAULTY COOLANT TEMPERATURE SENSOR.SEE IF ENGINE COOLANT TEMPERATURE SENSOR IS GIVING CORRECT COOLANT TEMPERATURE USING A CODE SCANNER.IF ENGINE IS 190 DEGREES AND THE ENGINE COOLANT TEMPERATURE SENSOR READING 100 TO 80 DEGREES COOLANT SENSOR IS BAD.HOT WIRE COOLING FAN TO SEE IF FAN MOTOR WORKS.BECAUSE COOLING FAN MOTOR COULD HAVE OPEN CIRCUIT CAUSING ELECTRIC MOTOR NOT TO TURN ON.

REPLACE THERMOSTAT BUT IT SOUND LIKE FAULTY COOLANT TEMPERATURE SENSOR.BUT CHECK COOLING FAN FUSE AND RELAY.IF ALL IS GOOD HOT WIRE COOLING FAN IF COOLING FAN WORKS.PROBLEM COULD BE FAULTY COOLANT TEMPERATURE SENSOR. DAMAGE FAN WIRING OR FAULTY PCM.IF COOLING FAN DONT RUN WHEN HOT WIRED.REPLACE FAN AND MOTOR.

HOT WIRE COOLING FAN USING JUMPER WIRES TO BATTERY.IF FAN DONT RUN WHEN HOT WIRED FAN MOTOR BAD NEED REPLACING. IF FAN RUN WHEN HOT WIRED. CHECK COOLING FAN FUSE AND RELAY.IF ALL IS GOOD.YOUR ENGINE COOLANT TEMPERATURE SENSOR NOT WORKING.IT CONTROL COOLING FAN AT SET TEMPERATURE IF SENSOR OPEN OR FAULTY THE COOLING FAN WONT TURN ON.CHECK COOLING FAN WIRES FOR DAMAGE.IF ALL STILL CHECK OUT GOOD HAVE VECHICLE SCANNED FOR PCM FAULT.IF IT FAILS NO COOLING FAN WONT TURN ON.

SOUND LIKE COOLING FANS NOT RUNNING CHECK AND SEE DOES COOLING FANS TURN ON WHEN ENGINE OVERHEATS IF NOT CHECK COOLING FANS FUSE AND RELAY IF BOTH CHECKS OUT GOOD HOT WIRE COOLING FAN.IF IT WORKS.PROBLEM COULD BE COOLANT TEMPERATURE SENSOR- PCM- AND OPEN OR SHORT IN WIRES.IF COOLING FAN DONT WORK WHEN YOU HOT WIRE IT PROBLEMS THE FAN MOTOR.

faulty temperature sensor. It's near where the thermostat lives in the motor. In an emergency you can wire the + side of the fan to the accessory panel, just know that the fan will run the entire time the car is on.

if the cooling fans dont come on, it might need the fan relay replaced.
the relay is located on the frame rail right below the battery tray. the easiest way to accesss it is from underneath the car.