OEM electric fans 2000 Sierra help!!!

**tznutts** · 03-11-2012, 09:07 AM

What OEM fan kit can I get that will fit my truck? I have a 2000 GMC Sierra 4.8. Someone told me that a 98-2002 28" shroud from an ls1 ta or Camaro fan and harness would work from a salvage yard and just have my PCM programmed for a electric fan and plug the harness in and roll? Can someone help me with this??? I want it work as if it were a factory electric fan. Don't want aftermarket relays and all of that... Is there a way to achieve this?

Thanks!!!!

**Firebirdjones** · 03-13-2012, 02:43 PM

They'll need relays to work properly. Not sure if your truck is equipped from the factory to accept relays for fans.

98-02 4th gen fans will work fine. I converted my 6.0 over to 2002 4th gen fans, but I was dropping the engine into something older, so the custom harness I had came equipped to run the fans with relays and fuses intact along with factory style weather pack plugs, I simply set the temps where I wanted them in the tune.

Not sure what you would do about a harness either, even if you grabbed the harness from a 4th gen with the fans, you would still have to run them to the computer somehow. Again, not sure if these trucks come equipped with a harness hiding in there for that or if you have to pin out the computer connections and find where they go??

It's not a new idea however, people are doing it on Trailblazer SS 6.0's for the added HP it free's up. So what you want is do-able, just not sure to what extent you have to modify things.

**Cutlass** · 04-13-2012, 07:03 PM

Nelson Performance sells the relay and wire harness to hook up LS1 fans (or any other fans) to the PCM to have the PCM control the fans. You also need to have the PCM tuned to used the fans.
The harness it about $110 and the tuning for fans cost $35 through them. Any tuner can also turn on the fans.

**prerunfw** · 05-25-2012, 06:22 PM

Did you get around to the install?

I picked up some trans am fans a couple months ago, just started mounting them today. The height of the shroud looks good but the width is a little short for the 28in core. I am adding some aluminum (the bent end pieces) to account for that. Then, the top/bottom have miter-cut alum. angle; no height change there. The edges that touch the radiator are getting 1/4in hose sliced lengthwise and safety wired to the aluminum. Hopefully I'll have em installed by tomorrow and post up. This is for a 2000 silvy btw

**ChevyIILS1** · 07-09-2012, 02:13 PM

Prerun that's a nice piece. I did the LS1 fans on my 00 rcsb and need to hook it up like yours. Could you pm the specs thanks.

**wishmasstir** · 07-09-2012, 06:30 PM

Did anyone use the replacement ls1 fans from Amazon? Their only $140 new

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**Firebirdjones** · 07-10-2012, 06:32 AM

Originally Posted by wishmasstir

Did anyone use the replacement ls1 fans from Amazon? Their only $140 new

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I used a complete LS1 dual fan assembly I pulled from a car in the junk yard....$50

**prerunfw** · 07-11-2012, 06:07 PM

*Junkyard fans for me as well. But I put new motors in so +$$$

What specs do you need Nicholas? The long pieces here are 1/8" by 1" alum. angle, the sides and corner gussets are 16th" or thinner alum. (thin enough to cut w/shears by hand). The side pieces are were about 4in. wide when cut, then I bent em to 45*. After cutting off the overhanging edges of the stock shroud, you can adjust for whatever width core you need to cover by sliding in/out the bent side pieces.

I installed (2) longer bolts backwards through the shroud, near the factory mounting holes to act as studs after the 1st nut.
This mock-up pic has the brackets on opposite sides, that's why the bends look funny. I also centered it up a little better for the final install.

**I prob have about 250 bucks wrapped up into the whole deal counting the fans (from junkyard), new fan motors, 2-temp sensor switch units, +custom wiring w/relays & switches). The temp sensor units are hayden universals (3647's I think). Then, I added a parallel manual switch/relay for each fan. Which side of the system is running (auto/temp-sensored 1&2 vs manual-1 and/or manual-2) is chosen through an SPDT relay, so that either auto or manual control is active and never both. 3 switches total; Siemens & Hella relays all around since I had em left over from previous projects.

**5.0THIS** · 07-12-2012, 12:08 AM

Why isnt everyone just using the electric fans that came on later model trucks that bolt right in?

**Firebirdjones** · 07-12-2012, 05:46 AM

Because those aren't as plentiful in the junk yards yet

**5.0THIS** · 07-12-2012, 11:10 AM

Originally Posted by Firebirdjones

Because those aren't as plentiful in the junk yards yet

I'd go the extra mile to find some just so I can bolt them right in and not have something rigged to fit that doesnt look like it was there originally. just my opinion

**wishmasstir** · 07-12-2012, 11:23 AM

The new fans are for 34 inch wide radiators also so you have to upgrade that as well unless you have a 6.0l in an older truck or other option packages

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**Firebirdjones** · 07-12-2012, 01:02 PM

Originally Posted by 5.0THIS

I'd go the extra mile to find some just so I can bolt them right in and not have something rigged to fit that doesnt look like it was there originally. just my opinion

If I were working on a new truck,,,and there were OEM parts out there to be had that bolt right on,,,,then yes I agree, I'd go that route as I prefer an OEM look, fit, and function.

I myself however was doing a completely custom 6.0 swap in my 72 blazer, so basically any dual electric fan would work for me. I didn't want aftermarket though, because again, I like that factory appearance and the longevity that comes with a well made part. The OEM fans give me that, and finding them on a 4th gen camaro is a walk in the park,,,,,or in this case the junk yard

**5.0THIS** · 07-12-2012, 11:58 PM

Originally Posted by Firebirdjones

If I were working on a new truck,,,and there were OEM parts out there to be had that bolt right on,,,,then yes I agree, I'd go that route as I prefer an OEM look, fit, and function.

I myself however was doing a completely custom 6.0 swap in my 72 blazer, so basically any dual electric fan would work for me. I didn't want aftermarket though, because again, I like that factory appearance and the longevity that comes with a well made part. The OEM fans give me that, and finding them on a 4th gen camaro is a walk in the park,,,,,or in this case the junk yard

I can agree with that on all parts. If I were to ever put electric fans in my 04 sierra, I'd have OE truck fans in there, even if I had to put in a 6.0 radiator. Although I do have the upgraded cooling system, so maybe I wouldnt have to. Not in a hurry though as, in my opinion, switching to the electric fans has very little to offer me. The manual fan doesnt run that often anyway, and when it does I couldnt care less about the few additional horsepower I could gain by the Efans

**Firebirdjones** · 07-13-2012, 05:55 AM

Originally Posted by 5.0THIS

I can agree with that on all parts. If I were to ever put electric fans in my 04 sierra, I'd have OE truck fans in there, even if I had to put in a 6.0 radiator. Although I do have the upgraded cooling system, so maybe I wouldnt have to. Not in a hurry though as, in my opinion, switching to the electric fans has very little to offer me. The manual fan doesnt run that often anyway, and when it does I couldnt care less about the few additional horsepower I could gain by the Efans

Sounds like we have that in common, I'm more of a mechanical fan person myself. They never die and you can always trust they will do the job

But you know me, I like all things old and don't deal with change well.

I only went the electric fan route on this swap because I wanted to clean up the engine bay a tad, and that mechanical fan shroud on a 72 blazer is "large x huge"

It was giving me fits when building the air intake system and keeping me from making a gradual turn out of the throttle body.
I was also hoping that running both fans would help to cool the AC condensor a little better when sitting in traffic. The jury is still out on that theory though.
I do like the extra room it made by going electric and the overal "open" appearance with less clutter.
The added HP is a plus I guess,

and it's supposed to increase some gas mileage. I do get phenominal gas mileage for what this thing is, and I figured it would be good, but I don't believe I can contribute that to the fan swap.

**prerunfw** · 07-13-2012, 08:54 AM

Valid points^. I couldn't find a set of the truck fans that day at the junkyards. I just did the swap because I was bored and wanted to reach a verdict first hand, not from all the internet heresay out there.

**5.0THIS** · 07-13-2012, 07:23 PM

Originally Posted by Firebirdjones

Sounds like we have that in common, I'm more of a mechanical fan person myself. They never die and you can always trust they will do the job

But you know me, I like all things old and don't deal with change well.

I only went the electric fan route on this swap because I wanted to clean up the engine bay a tad, and that mechanical fan shroud on a 72 blazer is "large x huge"

It was giving me fits when building the air intake system and keeping me from making a gradual turn out of the throttle body.
I was also hoping that running both fans would help to cool the AC condensor a little better when sitting in traffic. The jury is still out on that theory though.
I do like the extra room it made by going electric and the overal "open" appearance with less clutter.
The added HP is a plus I guess,

and it's supposed to increase some gas mileage. I do get phenominal gas mileage for what this thing is, and I figured it would be good, but I don't believe I can contribute that to the fan swap.

My uncle has a blazer of that vintage, so I know what you mean about the shroud, it is quite large. His is a carb motor though, so he has no such clearance issues. I've always questioned the gas mileage gain with efans; my fan runs so infrequently that it would have to be a huge difference in drag on the motor to make any overall difference in mileage, and I just dont see it. It does clean the bay up some though for sure.

**Cutlass** · 07-14-2012, 01:02 PM

I haven't done the eFans yet, I'm hoping to get better AC performance at idle. Some of these really warm days this year, my AC doesn't blow cold until I get the truck moving down the road. My buddy's 04 Duramax does the same thing. He tried a new fan clutch but I don't think that helped him.

**ChevyIILS1** · 07-17-2012, 03:15 AM

Thats what I was looking for. Thanks for the detail and pics.

**rel3rd** · 07-17-2012, 12:59 PM

Originally Posted by Cutlass

I haven't done the eFans yet, I'm hoping to get better AC performance at idle. Some of these really warm days this year, my AC doesn't blow cold until I get the truck moving down the road. My buddy's 04 Duramax does the same thing. He tried a new fan clutch but I don't think that helped him.

This is the 2nd summer for my truck and the LS1 fan swap. My AC definitely works better with the electric fans, as opposed to the old mechanical fan...no comparison. I used stock 2000 LS1 f body fan setup, Nelson harness and already have HPTuners so that part was free.

As a side benefit, once you install the electric fans, it opens up the whole front of the engine for a nice cold/fresh air kit. I made mine from a foot long piece of 4" exhaust pipe, a 4" 90 and a 4" to 3.5" adapter for MAF meter end. Just "flip" the stock upper radiator hose and it is completely out of the way and not dangling in no man's land like it would be if you didn't flip it...