Radiator Fans not working

Hello,

It sounds like it could be a fuse or relay not working but to be sure here are two guides and the cooling fan wiring diagrams so you can see how the system works with the fuse and relay locations as well.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

Yes, It was overheating and loosing coolant. We could not locate a leak, we replaced the thermostat and now we found that the fans are not working. Can you tell me where I can locate the fan switch and fan relays so that I can check them?

did you check for codes check fuses and relays under the hood

I checked the fuses but I am not sure the relays were checked. Is there a fan switch I can check? And what codes and where would I find them?

If its the switch or the coolant sensor check engine light would be on and
you need an OBDII reader to access the codes
most local part stores can help you in getting the codes for free
or use the OBDII reader for a deposit that you get back upon returning it
check with your local store for their policy

Will this reader tell us what the problem is then? Like a diagnostic?

Sure should tell something specially if have check engine light on
this is a site where you can check them and what they do

What if the CHECK ENGINE LIGHT hasn't come on. will that reader still identify the problem?

this reader will not , you need a scanner to communicate with the PCM (computer )and check what is going on
does the fan come on when AC on ?

I have the same problem both of my fans will not turn on ive checked the fuses but am not sure what else do as i do not have an check engine light on. the heat gage rises really quickly but does not quite over heat but it will if i sit for too long in traffic on a hot day ... it has ac and hot air perfect. 2008 grand prix 3800 v6

Hello,

It sounds like a relay could be bad or a fuse, Here are some guides and the radiator fan wiring diagram (below)

https://www.2carpros.com/articles/how-to-check-a-car-fuse

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken

The cooling fans on my 2006 Gran Prix do not come on. What is up?

That could be either the fan relay or the fan motor itself. Follow the guides and wiring diagrams below to troubleshoot the problem.



https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

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



Please run down these guides and diagrams and report back.
Cheers

Thanks for the guides. Replaced the relay and it is working great again.

Hi! I have a 2002 Grand Prix 3.1 engine and the radiator cooling fans will not turn on. I have replaced the sensor that is located under the throttle body, checked the fuses and replaced the relays still they will not turn on. I also purchased the other sensor for it but I cannot find the location where it goes. Can you please help? Thanks

See below.

If I turn the AC on the fans will come on. Otherwise they do not come on at all. If I disconnect the sensor under the throttle body the fans come on automatically but then my temperature gauge does not work.

Had the ect sensor and thermostat changed and the fan is still not coming on to cool the engine off. 2003 Pontiac Grand Prix SE 3.1L. What else could be the problem? Had the codes pulled up and they indicated that it was either fluid level, defective sensor and/or thermostat.

Test the cooling fan motor and the fan relay.

I have changed main relay for fans. It will work ok for a few day, then the relay burns out. Any help wounld be nice.Thanks

Check that the fan turns freely by hand, if the motor is firm or tight this can over heat and be a cause of the relay to fail.

I Replaced the thermostat, coolant, coolant switch and upstream 02 sensor because I was getting maybe 13 mpg hwy. My radiator fans will not come on I noticed recently and engine gets hot, also will shut off after idling at a stop. Fuse, relays, motors for the fans are okay a mechanic, not sure what the problem is?

Check for applicable trouble codes, anything? What is the temperature gauge showing?

I have got two new trouble codes 0053 and 0030. Since the repairs the engine temperature gauge reflects that the temperature needle is at 60% of total engine heat. Months ago, before repairs were needed it was 40% or below. I just had these above codes given to me and at the same time I had my alternator checked. The auto parts guy said it is okay. Then he checked the battery and said it is 50% and will not hold a charge, this is when the car has been off. Not sure if he is accurate.

I would have top check actual engine temperature in degrees. If those are P codes, it is for 02 heater circuit.

If the battery is down, we cannot do any testing. You either have to get it charged or get a new battery. Does the starter crank okay? If you use a digital multi-meter across battery posts, key and everything turned off, what is the reading?

With the work you have done on it, possible air in the cooling system?

Wow, I just noticed I am still getting about 12 or 13 mpg hwy on my car, put in new engine air filter and full synthetic motor oil the other day I have to mention. Back to what we were talking about. It may be the 02 circuit, the battery is not down completely. I think having this original battery though is the reason for engine to shut off at stops during idle. Starter turns the car over fine every time. As for the radiator fans not working it is has to be the wires from the fans, which I think is odd or the heater circuit which I could actually check real quick before even doing the temperature gauge, so I think anyway!? The fans not working do you think could be related at all to the battery is not holding its charge?

With the engine running, the alternator should carry the load. Did you use jumpers to see if fan will run off the battery, for testing. You should use an inline fuse.

I would have to check voltage and ground circuit at the fan relay/s.

I checked the fuse for the SIR sensor or 02 sensor, the fans as well and none are broke and just bought 2 alligator lead lines. I don't have a voltmeter. Does it mean anything if I just started the car up, disconnected the negative battery wire and the car still runs? Can I somehow test to see if the relays are good although I don't have a voltmeter?

If taking the negative battery cable loose means anything, I do not know what? I would not take anything loose with the engine running. Without a voltmeter or test light, hard to do any testing.

I found out that the Mass Air Flow sensor was bad, so I just had that replaced at a shop. They said the vehicle's computer though needs to be reprogrammed because that should fix the radiator fans. What's another name for the computer that controls the radiator fans? He also said (the mechanic) the car will still run pretty rough even though the MAF was replaced, but should help your 5mpg problem some. He referred me to the dealer for the computer issue. Because he said he can't reprogram the computer or replace it. I'm not sure if I should go to a dealer, I just called one and they want 130 dollars for one hour to look at it!?

Pcm controls the fan relays. A lot of places will charge 100 bucks just for the diagnostics, even if they don't fix it.

We have a 1998 Pontiac Grand Prix. Cooling fans work when AC is on, but they will not turn on when engine gets to 230 degrees Fahrenheit without the AC on. We have swapped relays, changed the coolant temp sensor....still no luck. Anything we are missing? We know the coolant 1 and coolant 2 relays are working because the fans come on with the AC. Not sure of the function of the other NO/NC relay.

Have you checked the coolant temp sensor yet?

yes i have already replaced it

What colors were the wires going to it?

Let me jump in here.............

Your car is responding exactly the way it was designed to. It was programmed to come on at 230 without A/C

Here is a description of the circuit from the service manual


ELECTRIC ENGINE COOLING FAN AND RELAY
These vehicles use 2,360 mm (14.2 inch) cooling fans to aid air flow through the radiator. Electric motors drive the cooling fans. These motors are attached to the radiator. Motor size varies with each engine option.
A coolant temperature switch activates the fan motors. This switch regulates voltage to the cooling fan relay. This switch operates the fan whenever the engine coolant temperature exceeds 11O°C (230°F). For location and diagnosis, refer to Diagrams. A transducer can also activate the circuit, depending on the A/C compressor head pressure going to the condenser.
The engine cooling fan relays provide the high current required for the cooling fan motors using a low current signal coming from the Powertrain Control Module (PCM) . This signal is a function of various inputs.
Refer to Diagrams for further information and diagnosis of the cooling fan relay.

Engine Cooling problem
1994 Pontiac Grand Prix 6 cyl Automatic 123000 miles

my cooling fans are not working and my car's thermostat is indicating that it is hot. What can possibly cause my fans to not work? Can it be my fuses and what will happen to my car if I continue to drive like that? What do you suggest I do and what must I check to confirm the problem a-z

Direct battery voltage to the fan motor if its comes on-start checking the fuse/relay/coolant temperature sensor/sender to include the thermostat.

Stop driving it you might end up with major damage.

Thanks for the jump in wrenchtech.

No problem. Happy Holidays