Engine cooling Fans come on after hood closes?

SHARLEE KUCHYNKA

MEMBER
2004 CHEVROLET SILVERADO
5.3L
V8
2WD
AUTOMATIC
130,000 MILES

My husband has the truck listed above 1500, we had the engine cooling fans replaced about 2 years ago and they are only supposed to come on when the truck gets over 210 temperature. Now when we close the hood the fans turn on. And when we open the hood, they shut off. These fans were put in specifically for his truck because it is high performance. Anyway, we woke up to the truck battery being drained this morning and now we know it’s because of the fans staying on. The truck started just fine yesterday, and fans acted as they have been, only coming on when the temp got over 210. So, I’m not sure if this would be a relay problem or a circulation issue with something not being ground off properly. But why would it just all of a sudden do this today? He can’t drive it down the road without the fans draining the battery since they are staying on now when the hood closes.

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

It sounds like the ground is loose for the fan control module (aftermarket, correct?) Or the fan controller is bad. If you can upload images of the system I can help.

Please go over these guides and get back to us.

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Saturday, July 29th, 2023 AT 2:58 PM

SHARLEE KUCHYNKA

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4 POSTS

Yes, we figured it was having to do with fan control module or wiring. Please let me know if these pictures help any further. If you need another picture, let me know.

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Saturday, July 29th, 2023 AT 5:54 PM

SHARLEE KUCHYNKA

MEMBER
4 POSTS

Also just wanted to let you know we did feel the metal part on the latch for the hood and it was very hot after only running for a couple min. Nothing else around it was hot like that so yes it tells me that there’s some kind of charge going through it. Your reply did help give us a place to start and my husband is going to try to check the things you mentioned above.

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Saturday, July 29th, 2023 AT 6:04 PM

SHARLEE KUCHYNKA

MEMBER
4 POSTS

My husband is going to take it up to the mechanic that has worked on the fans before but idk if it’s safe to drive with a charge going through the hood.

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Monday, July 31st, 2023 AT 6:57 AM

KEN L

MASTER CERTIFIED MECHANIC
47,643 POSTS

It sounds like the controller is bad or there is a bad ground on the system. Thanks for the images. I would remove the aftermarket fan system and install the factory unit; it will cool much better. Please let me know how it goes.