Engine/Transmission (1994 - 1998) Question for Flex A Lite fan owners

[JDKammin]

I was looking into the electric fan setup for my 96 truck. A statement in their ads does not recommend using the electric fans if your truck, trailer and load on trailer exceeds 18,000 lbs. Is anyone using these fans and pulling heavy loads? What would be the drawback of the electric fans and heavy loads. I figured with air coming in at highway speeds and 5500 cfm of air moving from the fans, cooling would not be an issue. Any input would be appreciated. Thanks.

 

[charlessmith]

I've got Flex-a-Lite fans on my '96 3500. My total max loads are right at 12,000 lbs, but I've run that up steep twisty mountain roads, and up long grades in the Rocky Mtns.

I've done OK with water temps, exhaust temps are usually my limiting factor that cause me to back off a bit.

My only complaint with the Flex-a-Lite fan setup is that I have to pull the fans & shroud to R&R the alternator. The passenger side fan motor is too close to the bottom alternator bolt to be able to pull it out, and it's a bear to get a wrench into the spring loaded belt idler to take the tension off the belt.

I've thought of replacing the passenger side fan assy rivits with bolts and captive nuts, so I can just remove the pass side fan instead of the whole shroud. To pull the shroud, I have to take the top radiator hose off to get room to pull the shroud assy.

Other than that, I've seen maybe 1 to 1. 5 MPG improvement on most driving.

 

[BLNRAY]

how often do you replace alternators?

 

[WDixon27]

i have had mine off many times to gain access to ac and cooling stuff, 2 bolts and a couple wires and it off on the normal truck, not sure on the electric fan but i can imagine

how often do you replace alternators?

 

[Shadrach]

FWIW I ran a Flex-a-lite fan on my 84 Dodge V8 and found it great in the winter for warm up and OK around town. But in the summer I had to take it off and put the stock one back on. It just didn't pull enough air when towing the trailer. One time on a hot day, with the A/C on, towing up a hill and going slow because of construction I couldn't get enough air and nearly overheated. Granted I had a smaller fan and a lighter load than you but if you are near 18k loaded you probably will get too hot at some point. Of course it will be in a remote spot and under oddball circumstances, but are you willing to take a chance and cook your engine? I won't get caught again.



Shadrach



ps Wanta buy a used Horton fan clutch? Pm me

 

[JDKammin]

How much air does the stock clutch fan pull?

 

[charlessmith]

how often do you replace alternators?

Heh. After the Flex-a-Lite install, I repleced the OEM alternator with a 200A alternator, and a couple months later had it back off for a week. When I get done screwing around, it will probably be another 200,000 miles before it's off again.



The 200A alternator wasn't because of the Flex-a-Lite by itself. I've also got Sport Headlights that burn all 4 bulbs on low beam, and a heavy current draw (~80A) setup to quickly charge the deep cycle batteries in a camper.

 

[Shadrach]

How much air does the stock clutch fan pull?

I could never get an answer on this but I know when my stock fan clutch locked up on a trip with my trailer my temp dropped by 10*F and my mileage dropped as well. Shadrach

 

[WDixon27]

i saw something on here once that was around 12k cfm at full song but cant verify

How much air does the stock clutch fan pull?

 

[monkeyman]

I havethe set up on my 2002 and love it, better AC for sure, never had a problem except for the control and the motors fried once, they covered both under warranty. I set it high in the winter and they never come on, truck warms up real fast. I would think that stock fan uses 10 HP? I suggest a switch in cab to turn fans on just in case control fails
Rick

 

[drag racer]

I love my Flex-A-Lite 262 on my 1999. Would never go back to a stock fan. I was running slightly higher temps in the hot AZ summer, but realized the grill inserts I was running were the cause. Changed to a style with larger flow area, and voila. I pull 10k, and no cooling issues so far...

 

[FHerault]

It might be a good thing in winter, the warm-up time must drop ?

Do you need a stronger alternator with the fans ?

 

[charlessmith]

Do you need a stronger alternator with the fans ?

Not for the fans themselves. The normal wiring for the Flex-a-Lite fans will turn them on when your A/C compressor is engaged, so on a hot day the fans are on quite a bit (due to the A/C) even if you are driving at road speeds and the engine would be cooling OK without the fans. The current use from this is not a problem.



My '96 truck with the fans also has a conversion to Sport Lights that use 4 bulbs lit when the headlights are on.



With the A/C and headlights both on, the OEM alternator output is plenty good.



If you are going to add some other heavy load, you m,ight consider a higher output alternator. In my case, the charging system for my camper can pull as much as 80A for a while. I know of another guy that had some hearing-damaging high outout sound system that needed more alternator outout. Other than stuff like that, I think you will be fine with the OEM setup.

 

[FHerault]

Thanks Charlessmith,

I also have the conversion to Sport Lights on my 97, and additional fog and spot lights on the bumper, but they aren't on all the same time... so It would be ok I think.

The winter is cold here, and I am concern about the warm up time, with the coolant heater and the oil heater it's not bad, it's just when you park somewhere without 120V...



Also, perhaps the electric fans take less power than the stock fan when it's hot and climbing ?

 

[Hammer]

I also run the Flex-A-Lite fans on my 98 and have been since they came out. They have done all I asked them to do and more and could not be any happier with them. I also upgraded my alternator when I did mine,except,I found out the hard way I should have done it when I did the install. I have the fans,a big FASS system and a stereo which was straining the electrical system when they all ran at the same time. I decided to change the alternator to the Mean-Green 200amp and when I went to do the work I found the issue with the fan motor and the bolt clearance.



I do not tow heavy so I can not attest to how they would work in a sustained pull or grade. I have only towed with my truck once since I installed them and when I did they worked as they should have and did not allow the truck to heat up at all. I did the install on mine for show season looks and got a great product to go along with it. Did they save me any fuel,who knows and did they add any HP,not really but what they did do was work flawlessly now for over 2 years of daily driving in all seasons and for that I am very happy... ..... Andy



P. S. -here is a link to my original thread from way back and it also has the alternator thread link in it.



https://www.turbodieselregister.com...sion/184940-flex-lite-262-fans-installed.html

 

[FHerault]

Thanks for the link, Hammer.

A lot of reading but very instructive...

 

[Swineheart]

I ran the flex-a-lite kit on my 97' and took it off after a couple of months when the controller burned up and they did warranty it. I was pushing my luck with the kit seeing I pull about a 15,000 pound trailer and the fans were always running. I did like the added 1 MPG when I used the kit,but the truck ran to warm for my comfort level. I still have the fan kit in the box with a new controller I haven't installed let me know If you go with one I'am interested in selling mine.

 

[FHerault]

OK Swineheart, I have to think about it...

 

[JohnBoy5]

so is there anyone that pully heavy loads in hills with these? i am thinking for me they are a bad idea... .

 

[MMcCallie]

Flex-A-Lite told me the stock Cummins fan on a 12 valve moves at least 10,000 cfm and that I should not use their kit since I have a big, heavy truck that tows heavy and goes off road. The electric fans can obviously move more air at an idle but not nearly as much at higher RPMs. There are other options out there like a custom plastic fan and Horton electromagnetic fan clutch like I have. I certainly wouldn't want any less cooling ability than what I now have.