Convert to factory dual electric fans on '04 Suburban

don0442 · June 16, 2015

I have an '04 Suburban amd would like to convert the factory clutch fan to the factory dual electric fans on the '05 trucks (I have an '05 GMC 1500 with these fans)

I am wanting to do this as factory as possible, that is, using factory components and wiring.

Is this possible?

Also interested in hearing about other mods to this year range truck.

Chris · June 16, 2015

Order harness from LS1fans.com and install it with fans. Then get a tune so they can be activated in the computer

Badass69 · June 16, 2015

Get the front lighting harness out of a 2005 to 2007 classic truck half ton. The e fan harness is part of it including the fuse box addition you clip into the fuse center. If you can get it from a wrecker you you can strip the 2 pin trigger harness from the computer connectors as well and add them to your wiring harness.

I had the LS1fans harness and it treated me okay but my buddies lit on fire lol. I installed it and it was simply the relays overheated and melted. It's pretty common with their harness to have the relays fail. The gm one for all intents never has any issues.

I strip the harness put of the lighting bundle ( it's taped on separately do its easy to strip), reloom it and then install it in the truck.

Mine all look factory because well... they are. I have done the oem harness swap 4 times now and it's a breeze honestly.

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WilliamBos · June 17, 2015

The rad in the 05 electric fan trucks is 34" wide vs 28" in your 04. May be an idea to get the wider rad too.

Good luck.

Chris · June 17, 2015

The rad in the 05 electric fan trucks is 34" wide vs 28" in your 04. May be an idea to get the wider rad too.

Good luck.

Suburbans had the 34" already. Same with the HD trucks.

WilliamBos · June 17, 2015

Thank you.

don0442 · June 17, 2015

Thanks everyone for the replies - Thats why I love forums like this one, its always a wealh of information.

6.2Midnight · July 7, 2015

Badass69,

Regarding the two terminals that go to the ECU, where exactly do the Blue and Green wires go? I seen a earlier post of yours from a couple of years ago, but you never mentioned where to terminate them. If it matters, I have a 2003 Avalanche, with a built 6.0.

Thanks.

Chris · July 7, 2015

Badass69,

Regarding the two terminals that go to the ECU, where exactly do the Blue and Green wires go? I seen a earlier post of yours from a couple of years ago, but you never mentioned where to terminate them. If it matters, I have a 2003 Avalanche, with a built 6.0.

Thanks.

There is a spot on each ECU plug. I cant remember pin numbers though. From pics I can see, i am not home right now, blue plug pin 42 and green plug 33.

6.2Midnight · July 7, 2015

Chris,

From a schematic I seen it was just the opposite, but that is online and not a positivly marked as the one I need for my truck. Do you mind verifing your info?

Regards.

Badass69 · July 7, 2015

Badass69,

Regarding the two terminals that go to the ECU, where exactly do the Blue and Green wires go? I seen a earlier post of yours from a couple of years ago, but you never mentioned where to terminate them. If it matters, I have a 2003 Avalanche, with a built 6.0.

Thanks.

Green wire lands in pin 42 of the blue connector. The blue wire goes on pin 33 on the green connector.

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Chris · July 7, 2015

I went off pin numbers not wire colors. I also used a picture from LS1FANS.COM which is the harness i used on my truck

6.2Midnight · July 7, 2015

Badass69,

Thanks, that is what I figured, but wanted to be sure before making connections.

Chris,

My reply wasn't to try and correct you, just double checking as I said, before sending power to the wrong place.

Thanks to both of you for trying to help, I hope this may clear up some confusion for others who may search for the correct information in the future.

Badass69 · July 8, 2015

It's all fresh in my mind as I just yanked another harness about a week ago from 2 different 05 trucks. One for the trigger wires in the pcm and the other for the actual lighting harness. I have to convert my buddies 2000 Chevy short box reg cab 2 wheel race truck to e fans lol. I am using the rad and fans out of a 2011 truck core support I have kicking around. It's a little different with the 0411 pcm but it just needs a relay for the blue wire and tapping the ac clutch wire as the pcm has no ac control pin to land the blue wire too. A relay is needed for signal conversion as the e fan harness uses ground for signal (as do pcms in general.. just ground ouputs) and not voltage.

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6.2Midnight · July 8, 2015

I've been gathering more info about this swap. With the harness and fans I have, is it necessary to tap in to the a/c clutch and add another relay so both fans kick on high when the a/c kicks on (like the Nelson harness does)? Or will I be ok with stock?

No a/c a/c

Low temp= no fans pass high

High temp= both fans low Both fans high