Electric fans enough for 3/4 ton XL that tows?

[bfourman]

Considering converting my 00 Yukon XL to electric fans. Do they move enough air to keep a 6.0L cool with 8k of trailer behind it? I have read that they turn off over a certain MPH, if the engine temp comes up on a long uphill pull, will the e fans kick on and pull enough air to keep it cool like a clutch fan engaging would?

I am hesitant to lose the guaranteed cooling power of a clutch fan but also like the benefits of the electric fans.

Thanks!

 

[SpinNice]

Yes, fans move plenty of air. I did the stock Escalade setup from a 2006 on all 3 of my trucks and they do just fine. 1 of which is a plow truck that always ran high temps and real high trans temps. Whoever turns on your fan controls in your ecm, can set the fan on / off temp to whatever you desire if your that worried. Now I’m not sure, but check with a tuner. You may be able to change the fan options while in tow mode, to not have fans shut off until a certain speed. In other words, have the truck act stock with standard on off temps while not towing, and while in tow mode, have a complete different truck. I programmed mine with hp tuners, but everyone says Blackbear is the way to go. Hope this helps.

 

[bfourman]

I already have a BB tune, so that will be the way I'll go. I have a list of things I want to update/change anyway.

As far as harnesses go, ls1fans or Nelson? I have read pos/neg of both. The likelihood of finding OEM locally is slim to none, probably end up with a Dorman or Spectra unit and aftermarket harness.

 

[SpinNice]

I already have a BB tune, so that will be the way I'll go. I have a list of things I want to update/change anyway.

As far as harnesses go, ls1fans or Nelson? I have read pos/neg of both. The likelihood of finding OEM locally is slim to none, probably end up with a Dorman or Spectra unit and aftermarket harness.

@ScottyBoy is your guy for that. Got my harness from him and it was flawless. But, better get in line, there is a long list of people waiting on his harnesses lol

 

[ScottyBoy]

@ScottyBoy is your guy for that. Got my harness from him and it was flawless. But, better get in line, there is a long list of people waiting on his harnesses lol

I'm fresh out of OEM harnesses for the time being. I pretty much ransacked every self service junkyard within two hours of me, and I got EVERY OEM fan harness that I could find. The ONLY harnesses still available around here are at the full service yards and they won't even sell them unless you want to fork out $150-$200 to buy the ENTIRE front wiring harness off the truck.
I've considered making some custom fan harnesses to offer for sale, but I'm just leery about the long term reliability of the relays. Especially since Nelson and LS1FANS have both had melting problems with theirs. I've seen some 80amp relays on Amazon and wondered how those would hold up to the current and the heat.

 

[bfourman]

As luck would have it I may have located a '05 Silverado 4.3L at a local yard. Rockauto shows the same P/N across the board for cooling fans so I am going to try and check it out tomorrow; hopefully I can scoop the fans and wiring harness both.

 

[Tonyrodz]

As luck would have it I may have located a '05 Silverado 4.3L at a local yard. Rockauto shows the same P/N across the board for cooling fans so I am going to try and check it out tomorrow; hopefully I can scoop the fans and wiring harness both.

I'm sure there's alot of curious member', here, including myself, on how these will work out. Keep us updated.

 

[ScottyBoy]

I'm sure there's alot of curious member', here, including myself, on how these will work out. Keep us updated.

I can confirm, that the 05 v6 trucks had the same fans as the V8 trucks. I've pulled a few myself. I'm not exactly sure about the radiator, but it's definitely wide enough to use the same fans so it's a 34" radiator. Probably overkill for a V6, but that's what all the 05-06 (and 07 Classic) trucks got.

 

[bfourman]

Ended up with the fans and complete front end harness and fuse block for the fans. They pulled for me, grand total of $117.

 

[Tonyrodz]

Ended up with the fans and complete front end harness and fuse block for the fans. They pulled for me, grand total of $117.

View attachment 190989

Great deal. Just gotta go through the harness and make sure it's all good.

 

[ScottyBoy]

Ended up with the fans and complete front end harness and fuse block for the fans. They pulled for me, grand total of $117.

View attachment 190989

Wow, that's a REALLY good price! And then add in the fact that they even pulled them too? Plus all the wiring, that's really a steal. The fans alone usually sell for around $100 at most yards.

 

[ScottyBoy]

Also, since you have a 2000, you will need to modify that electric fan harness to be triggered by the AC compressor. You need a relay to convert the positive wire on the compressor to get able to trigger that negative trigger on the harness. The blue trigger wire will be connected to that relay, and the green trigger wire is the temperature trigger and that one will need to be connected to the PCM. I did all this when I installed E-fans on my 2001 Burban with a Blackbear Performance tune. Go check out my install thread that I did, maybe it will help you out.

http://www.tahoeyukonforum.com/threads/i-installed-e-fans-on-my-2001.28336/

Also, if for some reason you would be driving/towing with the AC off, you could also end up wiring up a manual override switch to basically force both fans to turn on high. When the engine gets up to temp and triggers the fans on, both fans turn on low. But when the engine is up to temp AND the AC compressor is on, then both fans will be running on high. So you can essentially rig up a switch to turn the fans on just like the AC compressor wire will.

 

[bfourman]

Yeah I am going to go through the harness and strip the headlight/park light stuff that I don’t need.

It helps to be friends with the junkyard owner [emoji3]

Scotty I have read your write up a few times and plan on following it. Nice work!


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[bfourman]

Started with this mess:

And ended up with this:

Yes that’s the dining room table, my wife went to town for the evening [emoji3]

I seem to be missing the pin to run to the PCM, but there is a small 2 pin weatherpack connector just down the line from the fuse block with a green and blue wire, I suppose either find another JY truck and rob the connector or run my own wires? Pretty sure I can source a PCM pin online.

Blackbear was nice enough to activate the fans with my original tune, so that’s sorted.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

 

[Tonyrodz]

Started with this mess:

And ended up with this:

Yes that’s the dining room table, my wife went to town for the evening [emoji3]

I seem to be missing the pin to run to the PCM, but there is a small 2 pin weatherpack connector just down the line from the fuse block with a green and blue wire, I suppose either find another JY truck and rob the connector or run my own wires? Pretty sure I can source a PCM pin online.

Blackbear was nice enough to activate the fans with my original tune, so that’s sorted.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

Good thing your wife didn't see that!

 

[ScottyBoy]

Started with this mess:

And ended up with this:

Yes that’s the dining room table, my wife went to town for the evening [emoji3]

I seem to be missing the pin to run to the PCM, but there is a small 2 pin weatherpack connector just down the line from the fuse block with a green and blue wire, I suppose either find another JY truck and rob the connector or run my own wires? Pretty sure I can source a PCM pin online.

Blackbear was nice enough to activate the fans with my original tune, so that’s sorted.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

If you are missing the section of the harness that goes to the engine computer, you can actually just get a single pin and splice it into your harness. You really only need one because the green wire is the only one that will go to the computer. The blue wire will need to connect with the AC compressor trigger wire, but be sure to use a relay to change the polarity from positive to negative.
You can find a green wire with a PCM pin on just about any LS engine truck. Just unplug the computer and peel the wire loom back and look for a green wire. Then use a small pocket screwdriver or a pic to remove it from the PCM plug.

 

[bfourman]

Finally got a chance to get this done tonight.

Now bear with me for a few more questions. The fans run on low speed at startup, normal? With the A/C the fans kick to high but cycle on/off with the clutch. Normal? From reading my specs from BB I took it to mean the fans would run for a minimum of 90 seconds with the a/c to avoid
constant cycling.

Haven’t driven it yet, tomorrow we will see if I can feel a seat of the pants difference.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

 

[YukonXL04]

I have had the Dorman fans and ls1 harness for 4 or 5 years now. No problems from any of it. Parked on a 105* day, towing our boats in the same hot days... I love mine. Mainly for the ice cold a.c. no matter what. But also for the load off the motor.

 

[bfourman]

Quick update on this. So far I really like the efans. Towed the Jeep for a few hours without any issues, truck seemed to have more pep. Ambient temp was in the 40s, so not really a cooling system test.

I did have to replace the OEM high speed relay in the secondary PDC, when it went out it kept the fans from running at all, low or high. Luckily I noticed the engine temp creeping up on the ScanGauge while I was unhooking my trailer at home and was able to troubleshoot before any damage occurred.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

 

[bottomline2000]

Quick update on this. So far I really like the efans. Towed the Jeep for a few hours without any issues, truck seemed to have more pep. Ambient temp was in the 40s, so not really a cooling system test.

I did have to replace the OEM high speed relay in the secondary PDC, when it went out it kept the fans from running at all, low or high. Luckily I noticed the engine temp creeping up on the ScanGauge while I was unhooking my trailer at home and was able to troubleshoot before any damage occurred.


2000 GMC Yukon XL K2500 6.0/4L80e/3.73s/BlackBear tune

2014 Aerolite 282DBHS TT

Just want to confirm..u do not have an issue with the fans being on constantly regardless of temp of a.c. pressure? Meaning they don't cyle on until you are at temp or your a.c. cycles on?

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