How to troubleshoot why dua electric cooling fans are not working

If an engine runs hot due to a partially blocked radiator the electric fan would be running most of the time.

If the fan doesn't run at all it suggests it isn't working and while that alone is likely to cause overheating in many driving scenarios, it is worth noting a car with a well designed cooling system in good order should rarely need the benefit of an electric fan when cruising at light load mid speeds.

It is possible the car has reached an age where it would be worth giving the cooling system a birthday along with repairing the cooling fan - replacing the thermostat and flushing the system thoroughly, including ensuring the radiator core is clear and nothing inhibits the air flow...

Radiator Cooling Fans - Professional Mechanics Online

www.2carpros.com/articles/how-an-electric-cooling-fan-works

Aug 1, 2015 - Step 1 - There are primarily two types of engine radiator cooling fan, electric and manual. A manual fan is connected to the engine drive pulleys ...

article How a fan clutch works

https://www.2carpros.com/articles/how-a-clutch-fan-works

Sep 3, 2015 - Step 1 - A fan clutch function is to engage the fan blade to the shaft when heated which is mounted to the front of the engine attached to the ...

Improving an Engine Cooling Fan Using Design for Six Sigma

www.mathworks.com/.../improving-an-engine-cooling-fan-u...

MathWorksA key component of an engine's cooling system is the cooling fan, which ... a shroud to direct airflow through the radiator (image courtesy of Novak Conversions).

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.

Obstructed radiator or plugged radiator, I didn't think that the Liberty had a fan clutch, I thought that it used an electric fan.

Picture of cooling fan

In the case of an electric fan there are relays and sensors involved plus the ECM (computer) is also in the mix to make that fan work.

I would suggest having the cooling fan diagnosed before doing anything else.

Did you check the cooling fan relay's ? Your vehicle has three of them . Free wiring diagrams at http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine size . Under system click on engine , then under subsystem click on cooling fans . Then click the search button then the blue link . Learning how the fans work then testing the electrical circuits is how we as Technician solve problems like this . We don't ask if anyone has this issue an knows how to solve it . Someone else's fix maybe different from what it will take to fix yours .
The cooling fan's are computer controlled ,by the PCM - powertrain control module . When the engine coolant temp. gets hot enough the PCM see's this through the use of a coolant temp. sensor . When it reaches 212 degress the PCM energizes relay # 1 sending B+ voltage through both cooling fans to ground causing low speed .
Relay Driven Dual Cooling Fan Diagnostics

{: ) You didn't mention the model of your vehicle. Anyway, I admire your way of observation, and I'm sure you got the analogy by now. When the car is running, the engine rpm is higher, and so with the water pump, plus the wind velocity passing thru the radiator fins, can give sufficient engine cooling without the electric cooling fans. But when your vehicle stops, like sitting on a traffic, the engine rpm is lower, and so with the water pump, and there ain't enough wind to help.
This is why the electric cooling fans are very important in maintaining engine temperature at normal levels in any driving conditions.
Basically, the cooling fans are controlled by the engine control module (ECM). The ECM monitors input from various engine sensors and then will give an output signal based on its programmed instructions. The output signals will energize the corresponding fan relays, be it high or low speed.
You can start by checking first the easy ones like the fuses and relays. Cooling fans usually have square top transparent windows. Check the the underhood fuseblock label to locate. Might as well check all fuses to be sure.
Check the cooling fan relays for signs of overheating, and also for loose terminal seating.
Check the cooling fan if stuck, and also check the connectors if burned or melted. To rule out a defective cooling fan motor, you can check for continuity, or you may apply direct voltage to the two wires on each fan.
The mostv frequent cause of cooling fan malfunction is on the fuses, relays, and connectors.

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.

With mechanical fans, most overheating problems are caused by a faulty fan clutch - though a missing fan shroud can reduce the fan’s cooling effectiveness by as much as 50 percent (depending on the fan’s distance from the radiator), which may be enough to cause the engine to overheat in hot weather or when working hard.

Defective fan clutches are a common and often overlooked cause of overheating. The shear characteristics of the clutch fluid gradually deteriorates over time, with an average loss in drive efficiency of about 200 rpm per year. Eventually slippage reaches the point where effective cooling is no longer possible and overheating results. (On average, the life of a fan clutch is about the same as a water pump. If one needs to be replaced, the other usually does too.)


If the fan clutch shows signs of fluid leakage (oily streaks radiating outward from the hub of the clutch), spins freely with little or no resistance when the engine is off or wobbles when the fan is pushed in or out, it needs to be replaced.


With an electric cooling fan, check to see that the fan cycles on when the engine gets hot and when the air conditioner is on. If the fan fails to come on, check the fan motor wiring connections, relay and temperature sensor. Try jumping the fan directly to the battery. If it runs, the problem is in the wiring, relay or sensor. If it fails to run, the fan motor is bad and needs replaced.

Hope help with this.

MAKE SURE WATER PUMP WEEP HOLE NOT LEAKING.IF SO REPLACE IT.MAKE SURE YOU HAVE 50/50 MIXTURE OF ANTIFREEZE AND WATER.MAKE SURE YOUR COOLING FAN IS WORKING .IF YOU GOT A CLUTCH FAN IT SHOULD NOT BE LOOSE OR FREE WHEELING.IT SHOULD HAVE RESISTANCE WHEN YOU TURN IT BY HAND.IF YOU GOT ELECTRIC COOLING FANS TURN ON AC SWITCH TO SEE IF THEY COME ON IF YES FANS WORKING IF NOT COOLING FANS RELAY IS BAD.ALSO SCAN IT TO CHECK COOLANT TEMPERATURE SENSOR.TOO SEE IF MATCHING THE ENGINE COOLANT TEMP IF NOT REPLACE IT.IT WILL CAUSE YOUR COOLING FANS NOT TO COME ON AT A SET TEMPERATURE.CAUSING ENGINE TO OVER HEAT.. .

INSPECTION 1. Check for a burnt fusible link with an ohmmeter. 2. If a fusible link burns out, there is a short or some other problem in the circuit. Carefully determine the cause and correct it before replacing the fusible link. The fusible link will burn out within 15 seconds if a higher than specified current flows through the circuit Radiator 30A Pink