Radiator fan will not turn on

Good morning,

I attached a diagram for you to view for the cooling fan motor.

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

https://www.2carpros.com/articles/how-to-check-wiring

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

You will need to replace the entire assembly for the fan motor if you applied a direct current to the motor and it did not work. I attached diagrams for you for the procedure below.

https://www.2carpros.com/articles/replace-electric-fan-motor

Did you replace the dual control fan relay module? I also posted the procedure for you as this is a common failure.

Roy

Yes, I did check and relays were good.. bought entire radiator fan assembly. Just have to put it in. It was 116 in Vegas today.....

Okay, good. I assume you verified the voltage to the fan motor from the relay. Make sure you have voltage at that connector. That electronic relay was a very common failure for the fan not working.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Roy

Yes, it read 12v.

Good. Then replace the fan. Just wanted to be sure.

Roy

Thank you so much! I'll let you know how it goes...

Wait quick question. Does it matter what kind/brand fan I buy? Can I get universal or not?

You are welcome.

Always glad to help.

Roy

No to universal. They are tough to mount and wire.

I attached the part I would use from Rock Auto.

Roy

Problem! Put new fan in. It's not fan. No power coming to fan. Relays are good.

You stated there were 12 volts at the fans? Was that accurate?

You need to go to the electronic relay and test for power out that relay.

If you checked the relays, how did you check them? Does the dark green wire have power?

I already posted the guides for testing in my original response.

Roy

Forgive me I did not see all the posts and pics they are going to be very helpful tomorrow when I start from scratch again. The problem is it's 100 degrees at 10:45 pm. daytime temperatures reaching over 118. And I'm just a girl (no offense to other females). But no matter how hard I research I do not understand electrical. And this town is famous for so-called mechanics. I am going to have to go to Angie's List or look for a credible mechanic/electrical. do you have any pointers on how to find one, like ASE Certified? I'm not sure what to look for, but I can research the heck out of anything. So I guess I can say thank you so much for all your time and effort.

You are welcome.

Keep me updated and let me know what they find.

Roy

Thank you.

Make sure they can trace the circuit by the diagram I posted for you. You need someone who can read diagrams and do pinpoint testing.

Roy

Thank you. Can you tell.me exactly what to look for in an honest mechanic?

Experience. He needs to have a background in electrical troubleshooting. Without that, he is guessing at your expense.

Roy

Thank you again.

Anytime.

Thanks for using 2 CarPros.

Roy

Hi, sorry to bother you. I cannot seem to find a reputable mobile auto, electrical mechanic. One guy charges $120.00 an hour to diagnose it. I did however speak to another one told me to put radiator back in place, fill it with water or coolest. Leave radiator cap off.. Not to hook up fan. Start truck rev engine for 2 minutes if water shoots out from radiator (where cap should be) its head gasket.??? Then I'm being told there's another relay behind passenger headlight. But then there's conflicting reports that no my vehicle does not have relay behind headlight. There's 2 relays in fuse box inside hood. I have 2 relays for fan high and low speed. I don't know what to do.

Okay, he is correct but that is not the reason for no voltage to the fan.

Try this: Disconnect the coolant sensor wires and turn the key on. Hook up the fan connections and see if the fan kicks on.

I attached a picture of the location for you.

Roy

It's fixed!! Bad Relays and broken wire..

Good find.

Glad you are back on the road.

Roy

Thank you for everything!

You are welcome.

Always glad to help.

Roy

Well my Jeep is not fixed. The mobile mechanic ran a jumper inn the relay so fan would stay on. Which it does. But after approximately three minutes of idling, the temperature rose past 250. I had to shut it off, wait 10+ minutes and ran the heater on high to get home. I'm at a loss. It has got new radiator, hoses, thermostat, temperature sensor, fan assembly, it's not water pump. And made sure there were no bubbles in coolant lines. Any suggestions? I'm going to take out thermostat put it in pot boiling water to see if it opens...

Okay, I would more suspect a head gasket than a bad new thermostat.

https://www.2carpros.com/articles/head-gasket-blown-test

I would do a compression test to see if there are any air bubbles in the radiator during the test to be sure the gasket is not leaking.

You have covered all the basics with what you did but if it still overheats then the head gasket is the next check.

I attached the procedure for you below for the head gasket.



Roy

No, it's not head gasket tried 3 tests. I did notice the radiator overflow which was at full mark yesterday, is almost empty. I searched for leaks can't find any...

Did they do a leak-down test on each cylinder?

That is where they inject shop air into each cylinder 1 at a time and watch for any coolant movement in the radiator.

If the coolant comes up or bubbles, it is the head gasket leaking. Each cylinder needs to be tested.

My gut tells me that this is your issue.

Roy