Got e fans installed but won’t turn off after truck is off?

[robvilla]

674-00923 Dual Speed Electric Fan Control Wiring Harness Kit Compatible with Silverado Avalanche Suburban Tahoe Sierra Yukon Stand Alone Electric Fan Harness​

Used this harness from Amazon and everything checks out but I have to unplug my relay every time I turn the truck off or else the fans keep going. Would really appreciate if anyone else had this problem and explained what they did to fix it!!! Please and thank you!

 

[Tonyrodz]

What year is your truck? If it originally came with a clutch Fan did you turn the fans on with a tune?

 

[robvilla]

Yes I did get a tune, my Tahoe is 04 so didn’t come with them originally had the clutch fan.

 

[justirv]

Yes I did get a tune, my Tahoe is 04 so didn’t come with them originally had the clutch fan.

I would ask your tuner what are the on/off parameters for Fan 1 and Fan 2. Are both fans running with key off? Do they seem to turn on properly, engine temp, A/C on, etc.?

 

[robvilla]

They turn on properly yes, both fans stay on when engine is off. Engine temps are normal, A/C on is fine and everything.

 

[justirv]

They turn on properly yes, both fans stay on when engine is off. Engine temps are normal, A/C on is fine and everything.

Check the harness to see where your power to the fan circuits is tapped. Is it constant power or key-on power. As far as circuit, the ECU will send a ground signal to the respective relays to activate.

 

[robvilla]

Check the harness to see where your power to the fan circuits is tapped. Is it constant power or key-on power. As far as circuit, the ECU will send a ground signal to the respective relays to activate.

Tuner said they are on constant power currently.

 

[Tonyrodz]

I don't know if that Dorman harness is part of your problem, but no one has had good luck with any aftermarket fan harness. They usually melt eventually. There's a member here @ScottyBoy who sells OEM harnesses for a great price. He pulls them from the junkyard, cleans them up, re-looms them and makes repairs if needed. He also includes all the factory relays along with all the needed plugs. And as an added bonus he marks everything so it's virtually idiot proof. Oh---he also includes the trigger wires needed, one being the wire that feeds to the ECM.
Maybe you should look into his harness.

 

[Marky Dissod]

...
@ScottyBoy who sells OEM harnesses for a great price. He pulls them from the junkyard, cleans them up, re-looms them and makes repairs if needed.
He also includes all the factory relays along with all the needed plugs. And as an added bonus he marks everything so it's virtually idiot proof.
Oh - he also includes the trigger wires needed, one being the wire that feeds to the ECM.

You should DEFINITELY look into his harness.

Fixed it for you.

(Been lucky so far with my one-off customized harness, yet STILL going to acquire one from ScottyBoy as a backup ...)