Electric fans

[Giant]

I was over at Truckworld online and found an article about them putting electric fans in a Ford. I've also read post from people on here that have suggested it to get a bit more HP, TQ, and MPG.

 

Has anyone doe it yet? If so, how are they for reliability. I saw where you can buy new motors, fans, etc....How quickly do these things wear? I'm looking to put them on my 99 Yukon with a 5.7L SFI. With this much leather, and the amount of options in it, it won't see lots of dirt and mud until its much older and I strip/rebuild it as a bogger. So it would mostly be used for road driving and possibly towing in the future. I mainly wahnt it for the MPG increase.

 

What are your thoughts?

 

Here is the kit for my 5.7L

 

Here are instructions for a Ford. (can't be too much different)

 

-Robert-

[Dragon Slayer]

I was over at Truckworld online and found an article about them putting electric fans in a Ford.  I've also read post from people on here that have suggested it to get a bit more HP, TQ, and MPG. 

 

Has anyone doe it yet? If so, how are they for reliability.  I saw where you can buy new motors, fans, etc....How quickly do these things wear?  I'm looking to put them on my 99 Yukon with a 5.7L SFI.  With this much leather, and the amount of options in it, it won't see lots of dirt and mud until its much older and I strip/rebuild it as a bogger.  So it would mostly be used for road driving and possibly towing in the future.  I mainly wahnt it for the MPG increase.

 

What are your thoughts?

 

Here is the kit for my 5.7L

 

Here are instructions for a Ford.  (can't be too much different)

 

-Robert-

 

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Mine came with electric fans...

[pm26]

My truck also came with factory electric fans. it is too new to talk about the reliability but I can tell you about my experience with my car's electric fans. On my 99 Mazda 626 I had to replace one fan motor, which cost $ 140 for the part only. It just wore out at 140k miles. Each electric fan typically has its own relay, so these can fail too. Overall, these fans last a long time and are quitte reliable.

[Giant]

So I shouldn't be worried about loosing them and ending up stranded??

 

Also, how do the facrory installed fans monitor temp? This comes with a piece you press into the radiator fins. How accurate is that and is there a better way to do it? Maybe a wet sensor that gets readings from a radiator line or something?

[C & A s Dad]

I looked into this at depth for my 02 Yukon XL and finally decided to leave it alone beause I do tow a camper with my truck. The guys on the RV site I belong too do not believe they are the way to go for towing. They feel that if they were, the 3/4 and 1 ton trucks would come with them from the factory.

 

A couple to things to remember.

 

1) You will not produce any more HP or TQ from the engine, you will simply be moving it from being used by a mechanical fan to being avail for the rear wheels.

2) A properly operating fan and fan clutch is using almost no HP under normal conditions. Of course they pull a good deal of HP when they are engaged but they also move a lot of air.

3) The E Fans will pull a good load on your charging system. You would likely need to upgrade your alternator to at least 140 Amp. This is just my opinion. The possibility for issues would come in if you were stuck in traffic at idle, with the A/C, radio, wipers etc all running and the fans were coming on and off. The alternator produces only a portion of it's max capacity at idle and with a pair of fans pulling 50 amps or so, you need a really high amp alt to take care of this.

4) For the most accurate temp reading, you would need to tap into the water where the current temp sensor is located. This would be much more accurate than a sensor stuck in the radiator coils.

 

Not saying you should not do this, but you need to do it all the way so you do not have problems.

[pm26]

I must agree with the post above: either get it factory installed or leave it alone. As I said before, factory installed system are pretty reliable in my experience. Properly installed electric cooling fans must be tied to a wet coolant sensor and to the

A/C compressor clutch.

 

Some vehicles, like my 83 Mercedes 300SD (turbodiesel) have both systems. There is a fan clutch and an auxiliary electric cooling fan. The auxiliary cooling fan normally does not run and it come on when one of the following (or both) happens:

1. Coolant temperature sensor indicates high enough coolant temperature

2. A/C refrigerant temperature sensor indicates high enough refrigerant temperature (this car has a separate A/C refrigerant sensor mounted in the receiver/dryer)

 

I had a Nissan pickup with a fan clutch system only and it failed at 70k miles. New clutch cost me $ 100 just for the part. So I would say that both systems are about equally reliable.

[Giant]

Did they make a factory system for this year, and if not will the factory system from a later year work?

 

Thanks

-Robert-

[Perry]

I agree with some of C & A s Dad's post, but not all. With respect to horsepower I agree that you will not gain any but displace it to have more available at the wheels. I also agree that the most accurate temp reading would be with a sensor directly in the coolant but I trust that Flex-a-lite has taken that into account and make adjustments for that. The Flex-a-lite systems for newer GM trucks (with LS based engines) uses computer readings to turn on the fans that the computer gets from the coolant temperature sensor.

 

As for the charging system I disagree with C & A s Dad. The stock altenator (105 amp) on a 99 Yukon should be more than enough to handle electric fans without any noticable side effects. The system you linked to draws a maximum of 28 amps. But you have to consider that it will only draw that much with the A/C on and when engine temps are more than 10* above what your fans are set to come on at. If wired correctly and without manual engagement, the second fan in the system is designed to come on only when the A/C is turned on. Flex-a-lite systems are set up so that the main fan only runs at 60% until the temperature hits the preset temp and then it will gradually increase power until about it gets to 10* above the preset temp at which time it will be at 100%. Under normal driving conditions this systems draws as few as 15 amps. Other considerations are that by removing your manual fan will create less drag on the system which should let your altenator do a better job of charging your battery (uses the same principle that allows it to free up more horsepower at the wheels).

 

Perry

[C & A s Dad]

Perry, I was under the same impression about the charging system until I spoke with a representative of the company who provides us with our rotating electrial (starters and alternators). According to him, an alt produces approx 40% of it's max output at idle. This would mean a 105 amp alt would be producing approx 42 amps at idle. If the truck was in traffic at or near idle and the headlights, blower motor, cooling fan or fans as well as the radio, wipers etc, were all on, the alt would be producing far less than the amperage draw. On the other hand, a 140 amp alt would be producing 56 amps and would better handle this load. I cannot promise his info was 100% accurate, but he seems to know his stuff.

 

I still believe this is a viable set up and is to be considered for gaining some Rear Wheel HP and MPG. You just have to decide if the gains are worth it. I elected to stay with my manual set up because we tow a 6500lb travel trailer and where I live it can easliy reach upper 90s and low 100s in the summer. I just could not convince myself to take the chance.

 

PS I also researched the Flex a lite offering and if I were not able to find an OE unit from an 05 or 06, I would be comfortable in using their system. They had some real issues when they first introduced this unit but have since corrected them.

[Giant]

I want it more for the MPG then the HP. It's got enough HP for what I use it for. I just figure that if I can get maybe 2mpg increase out of it, it will more then pay for itself over the life of the truck.

[Perry]

I'm not saying that upgrading the altenator is a bad idea, just that it is not a mandatory thing to do if installing E-fans. If in addition to E-fans, someone is running an upgraded stereo system, power invertor, supercharger, and/or other power accessories, then yes it would be a smart upgrade.

 

My job involves installing my companies high power HF,VHF, and UHF radio systems in vehicles. Our systems draw up to 28 amps, we routinely install dual systems, and the vehicles we install on usually already have anywhere from 1-4 other VHF systems already on them that can draw up to 20 amps each. We have had problems in the past with some older vehicles that had 60 amp altenators but have never had a problem with any of the newer vehicles that have 110 amp alt on them.

 

Now I'm definitely not an altenator expert, but I can see where someone could come up with the 40% number. A cars idle RPM's is usually 40% of cruising RPM's @55mph, but I don't now that output reduction is at the same rate as rpm reduction (it would make sense, but I'm not an expert). Even if that 40% is accurate you would still have to idle your vehicle for hours on end to drain a significant amount from the battery. But if your idling then your draw from electric fans is reduced also, and once you touch the gas pedal then alt output is going to increase accordingly. On a side note, the system he is looking at is a higher output 5500cfm system, Flex-a-lite also offers a lower volume 4400cfm system for our trucks that draw less amperage.

 

Anyways, I don't mean to argue or be disrespectful. I just don't want someone to be discouraged from buying E-fans because they think their alt can't handle it. Because from experience a stock alt will be able to handle the addition of E-fans and a few other small power accessories without any noticeable side effects unless your vehicle idles for hours at a time.

[01 Suburban LS]

I added a factory electric fan assembly to my 2001 Suburban. Picked it up on craigslist for $80. I then ordered the wiring harness from Nelson performance that allows the PCM to control the fans like stock. Then instead of having my PCM programed to turn on the fan, I ordered a custome tuned PCM from wait4meperformance with the option turned on, except the turn on temps were lowered a bit. I am completly happy with how everything turned out. With the addition of the fans and engine tuning, I'm getting roughly 50 more miles out of a tank of gas with highway driving. Also my A/C blows wayyyy cooler at idle than it did before. Total cost for everything was just over $300. Best $300 I've ever spent on modifications.

 

The only thing I think I may need to do is upgrade the alternator. In addition to the fans, I have an amp and connections for the winch on our flatbed. Can anyone recommend a decently priced high power alternator for my 2001?

[bossier62guy]

I've got a flex-a-lite system installed on my 02 Silverado and it works like a champ. It's running fine w/ the stock 105 alternator and I even went and had the charging system checked by the local experts after installing it to be sure it would handle the load. The biggest plus as far as I'm concerned is the room under the hood. By the way the temperature, according to my gauge, is rock solid using the temperature probe inserted into the fins.

[Giant]

I added a factory electric fan assembly to my 2001 Suburban. Picked it up on craigslist for $80. I then ordered the wiring harness from Nelson performance that allows the PCM to control the fans like stock.

 

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Anyone know if the PCM on a 99 can control the fans this way also? I can't see why not, since its an OBD II system it (if I'm right) monitors engine temps.

 

I'll be ordering it here shortly, and when I get it I'll take LOTS of pictures of the install to share and place in the HOWTO section. Probably won't be until after X-mas though.

 

Also, since I don't tow anything, yet, should I just go with teh 4400 cfm one? Up here in DC if you get caught in traffic you can EASILY sit in bumper to bumper for a couple hours.

[01 Suburban LS]

I added a factory electric fan assembly to my 2001 Suburban. Picked it up on craigslist for $80. I then ordered the wiring harness from Nelson performance that allows the PCM to control the fans like stock.

 

<{POST_SNAPBACK}>

 

 

 

Anyone know if the PCM on a 99 can control the fans this way also? I can't see why not, since its an OBD II system it (if I'm right) monitors engine temps.

 

I'll be ordering it here shortly, and when I get it I'll take LOTS of pictures of the install to share and place in the HOWTO section. Probably won't be until after X-mas though.

 

Also, since I don't tow anything, yet, should I just go with teh 4400 cfm one? Up here in DC if you get caught in traffic you can EASILY sit in bumper to bumper for a couple hours.

 

<{POST_SNAPBACK}>

 

 

 

 

 

Heres a link to where I got my wiring harness. You can shoot him an e-amil and see what he says.

 

http://www.nelsonperformance.com/products.htm#fans