E-Fan Installed

[dbunn]

I finally got my 05 electric fan installed on my 04. It all works like a charm. If anyone out there is thinking about doing it give me a buzz and I can fill you in on any of the details. I know several other folks on this forum and a few others have done this install too. It is fairly simple. Later!

[rmk800ak]

how much was the fan? wouldn't mine installing on mine will it fit a 03 8.1?

[builderpaul]

I finally got my 05 electric fan installed on my 04. It all works like a charm. If anyone out there is thinking about doing it give me a buzz and I can fill you in on any of the details. I know several other folks on this forum and a few others have done this install too. It is fairly simple. Later!

 

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What did you use for controlls? I had my pcm programed to operate like an 05 but am having a hard time locating info on what 2 pins to use.

What engine temps and AC pressures do you have set up?

[PewterC3]

only the 05's have 2 pins for low and high speed control. the '04's back have only one pin (#42) that can be activated on/off at preset temps.

 

there are many ways to control the e-fans. a varibale speed controller (which many have had trouble with), a 2 relay harness using pin 42 (u need a manual switch so you can turn on the fans when the A/C is on yet the engine isn't up to temp.. plus u need your PCM programmed), or a 3 relay harness that allows them to come on at temp thru pin 42 plus another lead that activates activate them when the A/C is on (through a A/C ground lead). This way they have a couple of stages and are not 100% on or 100% off.

 

 

I have the 2 relay and a manual switch that have worked great. I am going to switch to a 3 relay tho so I don't have to worry about my wife srewing up my A/C because she forgot to hit the switch when she starts the truck with the A/C on!

[builderpaul]

only the 05's have 2 pins for low and high speed control. the '04's back have only one pin (#42) that can be activated on/off at preset temps.

 

Are you saying the pinout is different on an 05pcm? I don't know what year my pcm started out as but it is in an 04 and programed to operate as an 05. So I have an 05 pcm hooked up to an 04 harness. I have been trying to confirm if the fans will work before I do the change over because I had the same thoughts. I don't know how this can work if the pinouts were different. The truck is running fine with this pcm so nothing is different so far but I have yet to try the fan hook up. The 05 system uses 42blue for the low speed (both fans on slow) control and 33 green for the highspeed.

I think with a Nelson harness you use the 42 pin for one fan and then tie into the AC wire for the second fan.

I didn't know 04s even had electric fans so I don't know what pin 42 does on an 04 pcm.

[PewterC3]

not sure about the pinout...but my understanding is the 04 and down PCM cannot activate pin 33. If you have a '05 PCM in your '04 truck.....that's the first I've heard of being able to do that!

 

and 04's didn't have e-fans... though the ability to control one (pin #42) has been in there since 99 or 00.

[Mighty HD]

So other than being "cool" and having electric fans, what other purpose is this for?

[PewterC3]

my A/C is cooler then ever...especially in traffic at low rpms or idle....yet is still running the OEM freon charge. I don't even have to set it to recycle the air or "max"...and would probably freeze if I did. I also no longer have that PITA power loss and roar that happens when the fan clutch kicks in on hot days....that in itself is worth the upgrade to me.

[Black02Silverado]

Can the 05 electric fans be installed in an 02? It would be worth it for the extra HP, less noise and cleans up the engine compartment.

[PewterC3]

my truck is an '01 and though it's a 1500 it has a 6.0 and the 34" radiator. If you have the 28" radiator you would have to upgrade to the 34" or use some other type of e-fans.

 

and they do clean things up a bit:

[dewfpo]

I finally got my 05 electric fan installed on my 04. It all works like a charm. If anyone out there is thinking about doing it give me a buzz and I can fill you in on any of the details. I know several other folks on this forum and a few others have done this install too. It is fairly simple. Later!

 

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DBUNN,

 

It would be great if you could write up some tips on doing this with any photos you may have taken. Many of us here are contemplating doing this and wondering which fans to use, source for best price, wiring, and controls.

 

Thanks, DEWFPO

[Mighty HD]

I personally don't think it would be a good idea for my personal truck just yet. As for the a/c---it blows 35-40deg 99% of the time and I'm in the Florida heat/humidity.

 

BUT if it really makes that much of a difference for gas mileage--I'm game. I got the westers 89-93 tune and I gained about 3mpg from it. If I can nail another 2-4mpg It'll be worth it.

[builderpaul]

I personally don't think it would be a good idea for my personal truck just yet.  As for the a/c---it blows 35-40deg 99% of the time and I'm in the Florida heat/humidity. 

 

BUT if it really makes that much of a difference for gas mileage--I'm game.  I got the westers 89-93 tune and I gained about 3mpg from it.  If I can nail another 2-4mpg It'll be worth it.

 

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No way 2-3mpg.

I read a GM research paper about the change to electric fans. One reason to change to e-fans was for increase mpg. It said gains of .5mpg (thats 1/2mpg for the decimal impaired). It is a gain, and every bit helps, but don't expect a real noticable difference.

They even plug up the bumper holes now if you don't have recovery hooks. Claims of measureable (very minimal but I don't remember the figure) mpg gains do to better areo.

I want to change my clutch fan so I have room to replace that terrible looking intake tube with a single elbow.

[mitchntx]

So one just installes the electric fan, uses whatever device they are comfortable with to engage the fan and remove the manual fan/clutch assy.

 

That's it? anything to know about removing the fan/clutch assy from the water pump snout?

[asilverblazer]

...yeah that engaging device is the tricky part.