Radiator fan will not turn on

Tiny
WITCH1
  • MEMBER
  • 2004 JEEP GRAND CHEROKEE
  • 4.0L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 18,000 MILES
Vehicle listed above is a Laredo 4.0l straight 6 4x. Overheating because radiator fan stopped working. After I changed radiator, cap, thermostat, hoses, modules, water pump, temperature sensor. Fan will turn manually, bypassed it directly to battery still would not come on. Now question is, do I have to buy entire radiator fan assembly, or can I buy just electrical plug and or fan motor? Last this would be the problem since fan wouldn't turn on when wired directly, right?
Thank you for any input.
Thursday, June 17th, 2021 AT 2:25 AM

29 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
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

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Thursday, June 17th, 2021 AT 3:08 AM
Tiny
WITCH1
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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.
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Thursday, June 17th, 2021 AT 10:03 PM
Tiny
ASEMASTER6371
  • MECHANIC
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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
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Friday, June 18th, 2021 AT 1:32 AM
Tiny
WITCH1
  • MEMBER
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Yes, it read 12v.
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Friday, June 18th, 2021 AT 2:39 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good. Then replace the fan. Just wanted to be sure.

Roy
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Friday, June 18th, 2021 AT 2:53 AM
Tiny
WITCH1
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  • 15 POSTS
Thank you so much! I'll let you know how it goes.
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Friday, June 18th, 2021 AT 1:32 PM
Tiny
WITCH1
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  • 15 POSTS
Wait quick question. Does it matter what kind/brand fan I buy? Can I get universal or not?
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Friday, June 18th, 2021 AT 2:01 PM
Tiny
ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
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Friday, June 18th, 2021 AT 2:28 PM
Tiny
ASEMASTER6371
  • MECHANIC
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No to universal. They are tough to mount and wire.

I attached the part I would use from Rock Auto.

Roy
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Friday, June 18th, 2021 AT 2:30 PM
Tiny
WITCH1
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Problem! Put new fan in. It's not fan. No power coming to fan. Relays are good.
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Sunday, June 20th, 2021 AT 3:05 PM
Tiny
ASEMASTER6371
  • MECHANIC
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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
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+1
Sunday, June 20th, 2021 AT 4:12 PM
Tiny
WITCH1
  • MEMBER
  • 15 POSTS
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.
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Sunday, June 20th, 2021 AT 11:01 PM
Tiny
ASEMASTER6371
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You are welcome.

Keep me updated and let me know what they find.

Roy
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Monday, June 21st, 2021 AT 1:44 AM
Tiny
WITCH1
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Thank you.
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Monday, June 21st, 2021 AT 2:02 AM
Tiny
ASEMASTER6371
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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
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Monday, June 21st, 2021 AT 3:08 AM
Tiny
WITCH1
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Thank you. Can you tell. Me exactly what to look for in an honest mechanic?
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Monday, June 21st, 2021 AT 3:37 AM
Tiny
ASEMASTER6371
  • MECHANIC
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Experience. He needs to have a background in electrical troubleshooting. Without that, he is guessing at your expense.

Roy
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Monday, June 21st, 2021 AT 3:38 AM
Tiny
WITCH1
  • MEMBER
  • 15 POSTS
Thank you again.
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Monday, June 21st, 2021 AT 3:49 AM
Tiny
ASEMASTER6371
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Anytime.

Thanks for using 2 CarPros.

Roy
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Monday, June 21st, 2021 AT 3:51 AM
Tiny
WITCH1
  • MEMBER
  • 15 POSTS
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.
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Monday, June 21st, 2021 AT 9:39 AM

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