What causes both cooling fans to not run? - 1997 Acura RL

you can check the cooling fan by disconnecting the plug at the motor and run jumper wires from the battery directly to the fan motor it should run if its working if it doesn`t run then the cooling fan motor needs replacing. if it does run then check the plug for a bad connection. other things can cause this like the cooling fan relay, the coolant sensor that sends a signal for the computer to turn on the cooling fan by sending a signal to the relay.

Many engine control system faults can cause the radiator cooling fan to come on and run non-stop. Also, if your A/C is on or if you have your heating and cooling controls in DEFROST mode, this can cause the radiator cooling fan to come on (normal operation). Or there could be a cooling fan circuit malfunction (like a stuck relay) causing this to happen.

Check to see what mode your climate controls are in. If the climate controls are not in A/C or DEFROST modes, then you should have your engine control system properly diagnosed to determine the cause of the radiator fan being on continuously.

Also, if the Check Engine light is on, this is a clue that the engine control system is malfunctioning.

CHECK TO SEE IF BOTH COOLING FANS RUNNING ARE RUNNING WHEN ENGINE RUNNING START OVERHEATING IF COOLING FANS NOT WORKING CHECK COOLING FANS LARGE FUSES IN THE ENGINE COMPARTMENT OR YOU COULD FAULTY COOLING FANS THERMO SWITCH BOTTOM LEFT SIDE OR RADIATOR.IF COOLING FANS IS WORKING WHILE ENGINE RUNNING.RADIATOR CORES AND HEATER CORE COULD BE CLOGGED.COOLANT SYSTEM NEED FLUSHING. THE THERMOSTAT PARTIALLY CLOSED CAUSE ENGINE OVER HEAT.CHECK WATERPUMP WEEP HOLE IF LEAKING WATER PUMP NEED REPLACING.

One cooling fan runs when the engine reaches a certain temp. The second cooling fan is designed to run when the a/c is turned on, providing more air flow throw radiator. However, it will cause no harm or damage if both fans run at the same time, with or without the a/c turned on.

cooling fan will not come on until about 230 degrees, if fans still do not work. check the fuses and relay. if ok then run a wire to fan from battery.on fan side connection, run a wire from battery positive to fan connection. run a wire from negative to ground connection.if fan will not come on it is either bad or the coolant temp, sensor is bad. because this sensor send info to pcm from various running conditions. it is very important that this sensor works. it can cause;

Extended crank time when the engine is cold

Poor fuel economy

Spark knock

Lack of engine power

Erratic and/or high idle

Engine cooling fan stays running all the time

Engine cooling fan fails to turn on

Engine overheating

CHECK COOLING FAN FUSE AND RELAY.IF BOTH GOOD SCAN CAR TO CHECK COOLANT TEMPERATURE SENSOR FAULT CODE.THE PCM AND COOLANT TEMP. SENSOR IS WHAT CAUSE FAN TO RUN AT CERTAIN TEMPERATURE.IF ALL IS GOOD.HOT WIRE COOLING FAN USING JUMPER WIRES TO BATTERY.IF FAN DONT RUN REPLACE FAN MOTOR.IF FAN RUNS YOU HAVE SHORT OR BROKE WIRE IN THE COOLING FAN ELECTRICAL CONNECTOR.

A STUCK CLOSED COOLING FAN RELAY WILL CAUSE FAN TO KEEP RUNNING.REPLACE COOLING FAN RELAY.

If the fans are running long after the car is shut off, the fan relay is fused together. Unplug the cooling fan relay and get a new one. Don't drive it far without that relay though. Put it back in and drive to your supplier.