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Home » Public Forums » GMCnet » Electric Radiator Fans: Practical cooling from the mens mall to your coach!
Electric Radiator Fans: Practical cooling from the mens mall to your coach! [message #89312] Sun, 20 June 2010 13:04 Go to previous message
Duce Apocalypse is currently offline  Duce Apocalypse   United States
Messages: 824
Registered: May 2009
Location: Los angeles
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Senior Member
Well, I finally did it, with the death of my stock water pump, I decided to go ahead and put in a powerful electric fan system to eliminate the 10-12 lbs of rotating mass on the water pump and ungodly noisy fan clutch.

Now I know the conventional wisdom here says that aftermarket electric fans are not sufficient to cool our coach, and I might agree that the offerings from Hayden and even Flex-a-Lite leave a lot to be desired unless you buy their most expensive model, and even then it may not be enough.

So I thought what about OEM fans meant for high performance applications? immediately my mind went to the insane electric fans Ford put in the Thunderbird Supercoupes from 1989-1995! these fans had to cool a 3.8 liter prone to overheating and to top it off this motor came with a Eaton M90 roots blower! the fan is powerful, its an 8 blade 17.25 inch diameter fan with a 2 stage Siemens motor which moves 4300+ CFM at full tilt, now I thought, what about adding 2 of these fans? 8600 CFM should be plenty of flow, actually probably a little bit overkill, but hey go large or go home has always been my motto, and I still believe that more is in fact, still MORE! So off o my local men's malls I went in search for some T-bird super coupes...

Well I actually found 3 SC's and they were having a half price sale so that meant these babies were a mere $25 a piece! I removed the fans and shrouds that came with them, I figured I'd have a spare if one was bad because I intended 2 would be needed for the project. Well in fact I found that these fans were a little large, so to mount them I would need framing brackets from home depot to mount the shrouds around the radiator support frame rather then to the radiator itself like a traditional shroud. I also found that the oil cooler lines would need to be moved 90 degrees as to not interfere with the shroud on the fan to be mounted in the upper right corner, also a small bracket was screwed to the lower left corner to provide a mounting surface for the lower left fan.

I ordered a flex-a-lite 33054 Variable speed controller when I ordered my water pump from Summit (Thank god for bill me later, makes repairs on a budget easier), this unit is good for almost 50 amps, and is for their expensive 500+ dollar fan used on the ford super duty 7.3 diesel, it costs about $96. This controller starts the fans slowly at 60% and then throttles them up to 100%if the temp rises 10 degrees from the starting point, so say if you have the fan starting at 195 degrees, then if the coolant temp rises to 205 the fan will be 100% power by that time. this a great feature because it softens the drain on the charging system, and the soft start of the controller eliminates power surges and sudden loads on the alternator to keep the voltage regulator happy. The controller is also warranted for 1 year.

So after installing the water pump, and removing the original fan, I started the fitting process, now that I know how to do this, the hardest part is drilling the mounting holes on the upper radiator support bracket for the upper right hand fan. the rest goes in fairly easily once you see how everything sits in there. The rest is just a matter of wiring up the connections, power to the controller, and the wires to the fans, then a wire to the 12v switched source, and then temperature probe which goes into the radiator. The VSC also has provisions for 100% on when the AC clutch is engaged, and a manual OFF, or manual ON override switch to engage the fans 100% should you deem it necessary. I will add an override on switch a little later as well as hook up the AC which is currently not hooked up as it needs a new charge of refrigerant.

Well upon testing the fans I can tell yo that I was pretty much blown away, (Pun intended) I set the fans to come on when water temp in the rad gets to about 195* which is the point when the T-stat opens. so I started her and got her to temperature. finally I hear the fans spool up, they run for about 15-20 seconds! then shut off, they never got past the 60% power! granted the outside temp is in the 70s so not really hot but still! about 30 seconds later they come on again run for a brief moment before switching off, and here is the best part, IT'S QUIET! no more roar when the engine first starts. There is some drag noticed on the alt, when the fans first spool so I may need a more beefed up 100 amp job, but the fans are on so short of a time it doesn't matter if you keep the coach faster then 35 MPH the fans don't come on at all!

I also have a video which I am putting together so you will see the BFF's (Big Freak'n Fans) in action.

If anyone is looking for an electric cooling solution I highly recommend this, now I just need an actual road test to see if there is a mileage improvement, but there is definitely noticeable more power due to no fan drag.


Did I mention that its really quiet??

73 Canyon Lands, (a.k.a. The Yellow Submarine) West Los Angeles CA

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