Best harness for electric fan retrofit?
08-17-2017, 09:45 PM
#11
I can also confirm that a high amp alternator is a must when upgrading from a clutch fan to Efans. I installed 2005+ truck fans on my 2001 Suburban. I immediately noticed that my stock 130amp alternator wasn't up to the task of powering the fans, ESPECIALLY when I had both the front AND rear AC blowing on full blast. But that's when I needed the fans the most, to help my AC blow colder at low speeds or even sitting still at a stop light. I have since swapped my alternator for a 145a version with a smaller pulley, I've also done the "Big 3" charging cable and ground wire upgrade, and I have noticed a tremendous improvement. Don't get me wrong, I can still see a voltage drop when the fans kick on at idle, but other than that it's a non issue. I
08-12-2018, 02:15 AM
#14
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Tune
Having a difficult time finding someone that knows are has the correct equipment to tune my 03 6.0.
i recently bought efans for an 05 and a wire harness from nelsonperformance.
maybe silly question but I want to get them up and running but can’t find anyone to tune the computer and can’t be without my truck in order to ship the computer out to have done.
theres 2 wires that get plugged into the Ecm, and I’m guessing(have no clue really) that one is meant for temperature and other for a/c. If so, could I just tap the one meant for temp into the temp sensor and the other into some sort of a/c wire. I’ve looked at aftermarket fan controller which get installed as such but would like to keep a clean oem look as much as possible.
Any feedback wiuld be greatly appreciated,
thanks in advance
i recently bought efans for an 05 and a wire harness from nelsonperformance.
maybe silly question but I want to get them up and running but can’t find anyone to tune the computer and can’t be without my truck in order to ship the computer out to have done.
theres 2 wires that get plugged into the Ecm, and I’m guessing(have no clue really) that one is meant for temperature and other for a/c. If so, could I just tap the one meant for temp into the temp sensor and the other into some sort of a/c wire. I’ve looked at aftermarket fan controller which get installed as such but would like to keep a clean oem look as much as possible.
Any feedback wiuld be greatly appreciated,
thanks in advance
08-14-2018, 06:17 AM
#15
The 2 ECM wires are the speed control. Both are outputs (relay drivers). If memory serves the Nelson harness comes with the relays (3 of them), no?
To get a GM harness, you can just gank it off a junk truck. There's PLENTY of em in the boneyards. An 05 or 06 will have the harness, relays, etc. for sure, that will just drop in; there may be other years that will work, but I know those will for sure. No idea about buying it new.
1 active = both fans low; the other active = 1 fan high; both active = both fans high. The ECM already has all the temp, AC, etc. inputs that it needs; all that's required now, is to give it something to control.
If you assemble it without tuning, I don't think anything will happen. Or if it does it will be wrong. Stock, 1 of the 2 pins worked the AC recirculate function in some of the AC system options; the other is unused. All you need, is somebody with EFI Live, HP Tuners, etc. You go into that group of settings and enable them. The stock 05/06 settings work pretty good. You'll have to buy a license for your VIN for the tuner. That's how those softwares work: you buy the software and programmer and all that, and it programs some limited # of VINs; then for each addl VIN you have to buy another license. For EFI Live it's about $100 or so depending on how many licenses you buy at a time. Not sure how HP Tuners or LS1Edit handle it but I suspect it's similar.
To get a GM harness, you can just gank it off a junk truck. There's PLENTY of em in the boneyards. An 05 or 06 will have the harness, relays, etc. for sure, that will just drop in; there may be other years that will work, but I know those will for sure. No idea about buying it new.
1 active = both fans low; the other active = 1 fan high; both active = both fans high. The ECM already has all the temp, AC, etc. inputs that it needs; all that's required now, is to give it something to control.
If you assemble it without tuning, I don't think anything will happen. Or if it does it will be wrong. Stock, 1 of the 2 pins worked the AC recirculate function in some of the AC system options; the other is unused. All you need, is somebody with EFI Live, HP Tuners, etc. You go into that group of settings and enable them. The stock 05/06 settings work pretty good. You'll have to buy a license for your VIN for the tuner. That's how those softwares work: you buy the software and programmer and all that, and it programs some limited # of VINs; then for each addl VIN you have to buy another license. For EFI Live it's about $100 or so depending on how many licenses you buy at a time. Not sure how HP Tuners or LS1Edit handle it but I suspect it's similar.
Last edited by RB04Av; 08-14-2018 at 06:31 AM.
08-15-2018, 09:09 PM
#16
Here are a few links I've collected.
https://www.performancetrucks.net/fo...-chevy-484892/
https://www.performancetrucks.net/fo...h-info-536648/
http://lsx4u.com/images/Retrofit_Ele...structions.pdf
1999 to 2002 Vortec PCM Pinouts
If you are talking about the tuning, you just need someone to turn the pins on. The dealer can do it, there sponsors on here that are tuners can do it. I would think anyone who might do dyno tuning in your area can do it.. I have read that anyone with a tech2 with..... (something I don't recall) can do it...… If you're in CA you shouldn't be that far from a tuner.
I have asked in other places before, but I am still unclear if you could just get the pins turned on, and then do the swap after so there is no down time, but never heard a response anywhere.
https://www.performancetrucks.net/fo...-chevy-484892/
https://www.performancetrucks.net/fo...h-info-536648/
http://lsx4u.com/images/Retrofit_Ele...structions.pdf
1999 to 2002 Vortec PCM Pinouts
If you are talking about the tuning, you just need someone to turn the pins on. The dealer can do it, there sponsors on here that are tuners can do it. I would think anyone who might do dyno tuning in your area can do it.. I have read that anyone with a tech2 with..... (something I don't recall) can do it...… If you're in CA you shouldn't be that far from a tuner.
I have asked in other places before, but I am still unclear if you could just get the pins turned on, and then do the swap after so there is no down time, but never heard a response anywhere.
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adriver (08-16-2018)
08-17-2018, 02:38 PM
#19
if you could just get the pins turned on, and then do the swap after
I think it's kinda like one of the many reasons beer is better than women... you can have 2 beers at the same time, and they don't get mad at each other. Or at you.
08-20-2018, 04:53 PM
#20
IMO the best harness is the factory harness. As mentioned it is part of the headlight harness.
What's sweet about the OEM harness is the fuse/relay box snaps onto the side of your existing fuse box and gets power from your existing fuse box. It's super simple. The ground for the fan harness connects at the factory ground location under the radiator on the core support.
I put my harness in before I had the fan file loaded into my PCM so I just ran a power wire to the fan trigger wire for low speed and left it connected while I drove it for a few days until i finally made it to the tuner.
The 145 amp alternator is a great idea regardless of how much additional electronics you are running, but especially if you do the fans and also have and amp etc. i personally just get them from the junk yard for $50, hasn't let me down yet. Have done several of them and have a 50 page thread on it over at LS1tech, lots of people did the used 145 amp alternator and loved it.
What's sweet about the OEM harness is the fuse/relay box snaps onto the side of your existing fuse box and gets power from your existing fuse box. It's super simple. The ground for the fan harness connects at the factory ground location under the radiator on the core support.
I put my harness in before I had the fan file loaded into my PCM so I just ran a power wire to the fan trigger wire for low speed and left it connected while I drove it for a few days until i finally made it to the tuner.
The 145 amp alternator is a great idea regardless of how much additional electronics you are running, but especially if you do the fans and also have and amp etc. i personally just get them from the junk yard for $50, hasn't let me down yet. Have done several of them and have a 50 page thread on it over at LS1tech, lots of people did the used 145 amp alternator and loved it.