fan clutch to electric

i want to put electric fans on my 05 5.3.How hard is it and what do i need? Has any one done it? Power change?THANKS IN ADVANCE!

i don't think it would be that hard. THe easy way might be to buy the fans and shroud that fits on the 06 full size trucks and run an aftermarket controller. THere are two players that make a dual fan setup, flex-i-lite and perma-cool. And there are some good SPAL aftermarket fans that have a number of different mounting options. SPAL alos has was looks like a pretty "cool" fan controller.

I think there would be some power gained, but its not really going to be much and you are going to spend about $500 or more to find out.

I think I would try the GM factory setup with aftermarket fan controller and relay setup. Check the actual surface area of your radiator before you start to look at options. Measure the top to bottom and then between the tanks, side to side of the radiaor so you'll know what will actually work and what will not. I think Perma-cool or flex-i-lite might make a bolt on kit for your truck. I 've never used either (just have read about them) I have used SPAL fans and they are of good quality. THe high output 16" fans really move some air, but they also make some nosie, you might do well to consider the "S" shaped fan blades over the straight ones....

Not sure if the '03 is the same as '05, but I went with a set of LS1 fans from a salvage yard and a Nelson harness - about $250 total. And yes, it does help your overall hp.

Not sure if the '03 is the same as '05, but I went with a set of LS1 fans from a salvage yard and a Nelson harness - about $250 total. And yes, it does help your overall hp.


ok you got my interest. what cars do i get the fans out of? camaros? are they a single fan or a double fan? with the wire harnes from nelson i still have to get a pin turned on right? would a local dealer be able to do that?

Does this "Nelson" harness just tie in to the Factory Electrical Center some how?

Slowprocess would be a good contact for this as he's done it with his rig.

This is a very worthwhile mod. I'm currently using Ls1 fans, but LT1 fans work just the same. The fans come out of all fbodies. They are dual electric fans. The Nelson harness is a three relay setup that uses the stock fan hookups and ties into the stock pcm and ac. The harness has one wire with pin in it that simply plugs into the pcm wring harness. When you cut on the ac, one fan will come on constantly until the other fan is needed for cooling. Other fan controllers will work(such as the fllex-a-lite), but I've heard of many experiences with them melting down. You won't have this problem with Nelsons.

The only down fall to the Nelson Harness is that you need to have Nelson(or some other tuner) turn on the electric fan feature in the pcm. This will enable the pcm to activate the fans at the desired temperature.

Overall, I have $70 in the electric fans and around $90 in the harness.

Another option is going with the electric fans out of the new trucks. They are larger than the LS1/LT1 fans. Downfall here is that the most of your older style trucks have alot smaller radiator and the fans won't mount correctly without swapping. The LS1/LT1 fans are easy to mount up to the older smaller radiators.

a question for slowprocess,What kinda horse pwr did you get with those mods?1/4 mile?trq?

a question for slowprocess,What kinda horse pwr did you get with those mods?1/4 mile?trq?

All of my mods or just the electric fans/harness?

If all the mods....I'm making around 400 to the wheels on motor and another 100+ on the spray depending on what pills I feel like that day. :evillol:

Best time all motor on the crappy 3000 stall was a 12.40@106 spinning to a 1.9? 60ft and haven't gotten a good 1/4 with the spray.

I did get a 1/8 time on the spray.....7.40@93mph. Again that was on the crappy TCI 3000 stall. I now have a fuddle 3800 stall and the jets on the spray are alittle higher than the 100 shot now.

OK, I've found some fans on e-bay. They look like there is just the fans. No wiring or anything. Is there any thing else I need besides the Nelson harness and the adjustment of the PCM?

No, that's essentially all you will need. You will need to make two brackets to hold the fans on. Use the existing bolts and threaded holes on the truck for the tops of the brackets and drill some holes in the fan housing and bottom of the brackets and just use some bolts and lockwashers or nylon lock-nuts.

i installed fans from an 07 1500 into an 03 1500 actually (i installed the whole front clip) only they dont turn on im assuming it is computer related but i was wongdering if there are differences in the wire harness i know of one for sure

it was a blue and green wire about 2 ft long with a 2 pin connector that went blue wire into green compter connector at pin # 33
and green wire into blue computer connector at pin #42 that seems to be the lead from the computer that activates the relays.

another problem i have is the fans each have to wires one has a yellow and gray other has blue and black i was trying to get the fans to spin by using a jumper wire but couldnt i was thinking of direct power but dont want to ruin the fans any advice on how i shpould proceed would be greatly appreciated

i went today to a shop first they said they could reprogram my computer to kick them fans on. than they said i needed the computer off the 07 which i provided, neither worked.
so i went home and began going through the harness wire by wire and checked the polarity of the fans and tried to figur out what was going on in the fuse and relay box now am only more confused (one relay, the only 5 prong relay, seems to connect the fans in series wich produces a reduced speed, than connects both postives together when the relay is energized)

i assumed the fans should spin in the direction that would push air towards the radiator. but i couldnt really tell so i drew up my own wiring diagram of how the system and i double and tripled checked. i could only think that it must be wrong.
now where i stand i would like to know if anyone has a wiring diagram for that nelson harnes. and would also like to know at which point the the fans should turn on i thought by reading other informaation on various sites they should turn on in 3 stages sustainment of(low speed or single fan) need to lower temp (high speed) and when the AC is on if any one can provide any technical info plz do so we are to the point where i might just try and track down the clucth fan and radiator and go that route.

Yesterday I bought a twin fan set-up from a 2005 Tahoe, I want to install it on my 2000 Suburban. No wires, just two fans and the plastic mounting. Where can I get the pig tails for the electric motors?
From what I am reading the Nelson wire harness is the way to go. Where do you get this type of a harness.
I am betting that I do not have a fan control in my trucks computer.
Thermostat and manual control override?
I normally try to stay away from electric work.....

I found the Nelson Website. Looks like my questions will be answered. The wire harness looks great. I will contact them Monday.



Parts ordered last Monday. I will post when I receive them and get them installed.

Update,
Installed the electric fans and wire kit lastnight. I weighed the old clutch fan, 6 pounds. Wow, that is a lot of weight to have on your waterpump and to have to turn. I wonder how much hp it took to turn that?

Parts list,
Electric Fan set from a salvage yard, (Del City Pickup in Del City Oklahoma) $75.00
Wire harness and ECU From Nelson Performance (search Nelson Performance and wire harness for their web site) around $180.00 including the core charge on the ecu. (The ecu had to be set up for the electric fan to turn on the fans as needed. Computers are great)
The hardest part for me was taking the fan clutch off of the water pump. My neighbor came over and helped me out, Thanks Bill. I would still be out there if not for his help.
I track my mpg so in a few months I will have a better idea if there is any change.

Update,
Installed the electric fans and wire kit lastnight. I weighed the old clutch fan, 6 pounds. Wow, that is a lot of weight to have on your waterpump and to have to turn. I wonder how much hp it took to turn that?

Parts list,
Electric Fan set from a salvage yard, (Del City Pickup in Del City Oklahoma) $75.00
Wire harness and ECU From Nelson Performance (search Nelson Performance and wire harness for their web site) around $180.00 including the core charge on the ecu. (The ecu had to be set up for the electric fan to turn on the fans as needed. Computers are great)
The hardest part for me was taking the fan clutch off of the water pump. My neighbor came over and helped me out, Thanks Bill. I would still be out there if not for his help.
I track my mpg so in a few months I will have a better idea if there is any change.


It will be interesting if the alternator will be able to handle the extra load.....

So far so good. Mine has the larger alternator on it. It does have over 140,000 miles on it so who knows how long it will last. I have been using the suburban for the last few weeks. We towed our boat to the lake over the weekend and had no problems. Temp was fine.
I am thinking of installing a switch to turn off the elect fan when I am on the highway and the A/C is on. That is the only change I would make. I have not checked the MPG yet but should have some data soon. ( for the first few tanks anyway.) Time will tell.

So far so good. Mine has the larger alternator on it. It does have over 140,000 miles on it so who knows how long it will last. I have been using the suburban for the last few weeks. We towed our boat to the lake over the weekend and had no problems. Temp was fine.
I am thinking of installing a switch to turn off the elect fan when I am on the highway and the A/C is on. That is the only change I would make. I have not checked the MPG yet but should have some data soon. ( for the first few tanks anyway.) Time will tell.



I believe on the electric fan vehicles the fans shut down at 40-45mph ....with the a/c on...


the elecric fans are a great help if stuck in traffic when the temp is above 90deg f...keeps the a/c condensor cool so that the compressor has less stress on it..

Well I'm back. I sold the suburban just after the last posting but I have made an offer on a pickup tonight so I will start looking for another electric fan to remove the clutch fan set up.

Got the truck,
A 04 silverado 1500, short bed single cab v6 auto.....
So can I put a twin fan setup on it? The mods start!

Well I am now in the market to put the factory electric fans on the silverado. Just can not seem to stop this mod bug....

fan clutch to electric thanks for sharing this post.

New Fans arrived today. I will call Nelson as soon as I make sure the fit is correct. Might just have this working by early next week.
Then I can.....well I will think of something else to modify.

You can find the wireing pigtails on the Rock Auto web site.

What was the solution relative to the PCM.... What temps does your truck run now with the electric fans?