My clutch fan was going bad so I did a little digging and decided to try an electric fan conversion. A big thanks goes to FordF250HDXLT, who pumped a lot of great research info into this thread.

https://www.ford-trucks.com/forums/9...onversion.html

I used a 2003 Windstar dual fan setup and fit it inside the existing shroud. Trimmed a little plastic from both the old and new shrouds, riveted them together and used a little aluminum sheeting to close it in. I also used a Derale 16749 controller and added 1 additional 30 amp relay for the second fan. The controller gives me adjustable temp ranges up to 240 degrees and an A/C override. Total cost was somewhere around $100 for the fans, controller, wiring and all.

The verdict is still out on performance, it will likely be a while before I pull anything heavy.

I'll let the pictures do the rest of the talking.



Wired and painted


I used the shroud as a terminal block for easy in/out in the future. The 4 posts from left to right are -12v, Key on, A/C and +12v. You don't see it here, but I also added a small switch to the A/C circuit just above the connectors to disable the fans in the colder months when the defrost is running and I don't need the cooling.


Close up of the controller (a little to close). I think I'm going to have to relocate this though because it's way to hot for longevity.


I realize I don't have any pics of the installed product. I'll have to add those.

Bob

 

great job Bob.looking forward to the installed pics,and your opinion with them after you run 'em for a while.
it's so good to see someone else do this too.they really work great.

 

Update: Temps are warming up a little here in Tennessee so the fans actually kicked in a time or two. I actually worked them pretty hard one day last week when I pulled out of the quarry with a load of crushed rock and tipped the scales at 20,380 lbs. Cruised up all but the last hill with ease, 4th gear 60mph ~2400 rpm, not bad for 3:55 gears.

I live in the Smoky Mtns and the last bit is up a steep gravel grade with a decent switchback part way up. It requires 4wd Low range and it was a pretty tough pull in 2nd gear (ZF5), 3rd gear couldn't hold it.

The downside was the wiring and controller location. In the last pic above you can see an inline fuse in the middle of the picture. It melted to a little green blob before it finally quite. Thankfully, I was in the driveway before it gave up.

So the only change so far has been to reroute all the wiring down low and move the controller, relay and fuses off to the drivers side. I chose the drives side because the temp sensor is plumbed in on that side.

 

the description of how your fuse blew tells me its overloaded. fuses should never be loaded past about 80% of their rating, or they will get hot and meltdown like that. you commented its a green fuse, tells me its a 30a. drop a 40a in there and it should be fine. two fans is a lot of load on the circuit. looking back at your pic, you've got a standard size fuse holder, you'll need to step up to the bigger fuse size. you can find them all over the junkyard or in your local parts store

 

Good point. Never thought about heat from circuit load. Each fan has it's own fuse, but I will look at upgrading both.

I also think I may have a problem with one of the fan motors. The smaller of the two moves a lot of air, the larger makes all the same noises but feels like it barely moves 10% volume and it's the one with the melted fuse. I did confirm that it is turning the right way.

Maybe one of the more electronically inclined here could tell me how to use mutlimeter to test each motors draw and what I should be expecting for each?

 

I have been considering doing this myself but just by looking at your pics it looks like you could fit four of those if arranged properly

 

yeah, i never thought about the circuit load until after my first meltdown. it was 110w of lights on a 10a fuse. calculates to 9.2 amps, so my high-school mind thought a 10a fuse would be perfect. upon later inspection, it was melted like yours but hadn't blown. and it was installed under the dash where things were cool. that was years ago, and i haven't repeated that mistake since then

for your troublesome motor, how freely does it spin? possibly a problem in the bearings or something. also, i see its blades face the opposite way of its brother, i assume you have them both pulling air the right direction, even though that probably means opposite direction of rotation...

 

They do spin in the opposite direction from each other. The blades spin freely so maybe brushes are bad. The blades on both look like they have the same slope to them but the motors look very different. They are both just 2-wire so I'm taking that to mean they are both single speed motors.

I figure i'll have to just break down and go get another pair and see how they compare. If nothing else I'll have a spare set.

 

iirc the oem windstar fuses are 30a for the smaller fan and 40a for the larger fan motor.
since we wire them on to spin together,this means we want a 70a rating.i went with dc controlled 85a variable rate controller after issues with the relay based first too.

if you hot wire (or switch on) one fan at a time to feel the flow difference with your hand under the hood,you can notice the larger fan motor is more powerful for sure,however not 90% more like you see.you seeing only 10% of the airflow from the smaller motor clearly tells me that fan motor is shot.

 

I am definitely under amp'd then with a 30a on each and likely a bad motor. I feel even more confident now that the big fan is bad since during my bench testing it is the big one that feels like it only moves about 10% of the small one. Off to the bone yard we go.

Thanks

 

F250, how much was your DC controller? If i ever get my 92 this is one of the things i want to get done when i have everything out/ apart

 

a couple hundred.
FK-85/L101/TADJ

Constant Temperature Controllers and Accessories