Just installed a flex a lite 270 dual electric fans on my 2001 F-150 with a 5.4L. The install took about 4 hours. I didn't want to remove any hoses, so it took a little time to work the old fan shroud and to work in the new fans. I also had to rent a fan clutch wrench from AutoZone. It was a deposit of $30 which they refunded when I return the wrench. I took my time with the wiring to give it the dressed up look. After I had the fans installed and the wiring installed and checked out it was time to set the VSC (Variable Speed Control). This is one of the nice thing about the Flex a Lite 270. I didn't like the way the instructions explained to set VSC. I used a thermometer with a 0 to 500 degree range. I placed it just above the Flex a Lite temp probe. I set my set my fans when the outside temp was 82 degrees. I set the fans to come on at 205 deg. This is 10 degrees above the full open for my truck's stock thermostat. I'll update everyone on the gas mileage. It feels like the acceleration is better. I got my fans off Ebay for a great price so I happy with them.

My truck is a 4x4 so I'm making an auto shutoff switch to cut the fans off when I am in water up to the frame. I am also making a switch to shut the fans off when the truck is above 40 mph. At 35 mph to 40 mph, there is more air being rammed though the radiator than the fans pull. At this speed the fans are just using up amps.

 

If your fans come on over 35-40 mph, that means there isn't enough air flow through the radiator to keep the temps down. Do you know for a fact that they are coming on? If those speeds ram more air through the radiator than the fans can pull, then why are you getting hot enough to turn the fans on?

I think you will find that the fans pull much more air than what is forced through the radiator while you are driving.

 

I think what mrjamjam was referring to is the fans running when the AC is on, regardless of the coolant temperature.

If the controller is wired so the AC can kick the fans on, it will turn them on every time the compressor turns on, even when you are driving at highway speeds and don't need them.

Not even close. The fans can move 5000 CFM in open air. They are not that efficient when trying to pull air through the condenser and radiator. If you do the math regarding the surface area of the radiator, combined with the velocity of the vehicle, you would see the fans are way behind at anything over 25 MPH or so.

I have had the FAL 270 for several years now. Great kit. I too did not want my fans to run when it wasn't necessary, so I installed a board that disconnects the AC output wire whenever the truck is going faster than 30 MPH.

 

I would be intereseted in seeing how you did this.

Thanks Bob

 

Make sure you guys get the recalled main fuse assembly replaced. My fuse assembly melted on me last weekend. I've got the replacement and will be splicing that in shortly. Great kit though. Good customer service too.


I also wired in manual override switches so I can run or cut off the fans, even if the AC is on.

 

Mrjamjam,
Who was the vendor on e-bay? and if you don't mind my asking, what did they sell the kit for?

THanks.

 

OK, that makes sense about the AC.

Anyone know the CFM rating of the stock fan?

 

Yes I'm wanting the fans to shut off when the AC is on and I'm running over 35 MPH. I have the fans set to come on at 205 F w/o the AC being on. This works great. On a 90 F day in traffic the fans are coming on at 60% and cycling off after just running for a few minutes. The truck temp shows normal all the time. Driving over 40 mph I haven't heard the fans cycle on. I may need to wire in a light to tell if they do or not. I don't think the fans are coming on unless the AC is on. With the AC the fans run full time at 60%.

I'm still checking the MPG to see if I get any improvement. I'm hoping for 1 to 2 MPG.

If you have a board that will tie into the CPU and shut the fans off at a given speed, could you tell me whom you got it from? Is it available for all of us?

IF you have a 4x4 and do any water crossing, the auto water switch is really nice. They shut the fans off when water reaches the frame.

I bought the fans off ebay from an individual.

 

Did you get an improvement in your MPG? Also, how are the fans working...well?