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View Full Version : Electric fan conversion.



bbrewer2005
01-31-2018, 06:23 AM
Ok, so I did a search and didn't find much. I plan on ditching the clutch fan for an electric on my 89 ram 50 with the 2.6l. I know how to install one, I just had a few questions for the guys that have. I have only done this on v8s that were already making near 300whp or better, never to an engine that made less than 100hp to the wheels. Most of the engines I've done this to, you can't tell much of a difference power wise.

My question, to anyone that has went electric, did you notice a power or fuel efficiency difference?

Also, did you upgrade the alternator? If so, what route did you take? I understand these are super low amperage alternators from the factory, like 40 amps or something silly. The fan on my race car draws about 25-30 amps at full speedand has a 220amp alternator. Lol The fan I have, and planed on using, draws 12amps.
I have the factory alternator from my race car (95 cobra), which is 130 amps, and has an internal regulator. I was thinking I could make a custom bracket and put the alt where the a.c. compressor goes. Any pros/cons or anything I need to lookout for specific to these trucks?

Thanks again!

geezer101
01-31-2018, 08:40 AM
I did the electric fan conversion to a project a long time ago (think Dodge Colt wagon with a 4G52/A904 trans combo). I noticed an improvement in throttle response. I didn't need to do an alternator upgrade as the 4G52 already had a higher output amp than the factory 1.6. It definitely kept the engine cooler and made it easier to get my hands around the front of the engine. When it came to replacing belts it made it a breeze. As long as you have the thermo switch installed in the right place it won't be pulling power for long enough to become an issue. I wasn't able to compare fuel economy before/after the thermo fan upgrade as the donor engine came from a Scorpion (Sapporo) and the Scorpion was a tank while the wagon was a canoe with wheels, but I would say it would have a small effect on fuel economy. The mechanical fan definitely causes a parasitic loss of power and with smaller displacement engines, anything you can do to reduce power losses has a cumulative effect.

tortron
01-31-2018, 09:38 AM
Will be fine on the standard alternator. I have one on my little flathead and it has the original generator. The fan will only come on briefly and should shut off when cooled down. You should have plenty of backup in the battery if for some reason you get stuck in traffic, at night, with the heater and radio going.

bbrewer2005
02-10-2018, 05:05 PM
So I was playing around with the truck today as I had some free time. Looks like the stock alternator isnt going to come remotely close to cutting it. The fan I originally planned on using just doesnt move enough air. Heats up when at lights.
The fan I chose is a markVIII ford fan (very similar to the taurus fan). These are common with electric fan swaps as they are abundant at junkyards, are super cheap, and move a TON of air, over 4000cfm. The downside, they draw upwards of 70 amps on startup and about 30-35 amps once at running rpm. I ran some wires straight to the battery while the truck was running at night to see how it would respond. It drops the rpm, and dims the headlights pretty bad.
I've already done the "Big 3" upgrade to the wiring. 0ga welding cable for batt to chassis, 8ga from engine to chassis, and 4ga from alt to battery. It has a fairly large AGM deepcycle starting battery. (had to modify battery tray and hold down) This was all done for the stereo system thats in it.

So when it warms up this spring, I am going to make a custom bracket to mount this 130amp ford 3g alternator I have laying around. I plan on trying to modify the ac compressor mounts to get it into the truck, as I dont think there is enough room for the considerably larger alternator down there where the factory alt mounts. When I get around to it, Ill post pictures as I go for future reference, possibly a sticky. I think the hardest part is going to be finding the correct size v belt pulley, so it puts out its rated current. I dont want to under, or overdrive it. It has a serpentine pulley on it now.

pennyman1
02-10-2018, 05:38 PM
use a small case GM alternator instead - much smaller, and at least 105 amps. it will fit under the a/c compressor, but you may have to modify the upper bracket where the alternator attaches to make it work. The mount needs to be extended forward to align the pulley of the alternator with the other pulleys.

risingphx25
05-29-2018, 09:27 PM
use a small case GM alternator instead - much smaller, and at least 105 amps. it will fit under the a/c compressor, but you may have to modify the upper bracket where the alternator attaches to make it work. The mount needs to be extended forward to align the pulley of the alternator with the other pulleys.

Pennyman1, as far as the harness to the alternator just splice in the connections from the GM alternator to the stock Alternator? I have a taurus fan lying around IŽd like to put to good use.

dash
05-29-2018, 11:41 PM
Years ago I adapted(made bracket) a GM small case 105 Amp alternator my starion 2.0 corolla swap. Worked great
think it was a single wire hookup, with the 'exiter' turn-on wire routed thru the dash warning light bulb

Never liked those power-hog Taurus fans, ridiculous amp draw
Can't remember which oem single fan (cheap junkyard) i used, but it only spiked ~17 amps, then settled to ~10 amps running
.....read on a small battery charger dial gauge
solid air flow n kept cool easily. Hayden ajustable fan thermostat/relay

Mechanical_stig
07-22-2018, 10:36 PM
I did a high amp draw 16" 2500 cfm fan with stock shroud, just a 30amp key on relay, and it is great with throttle response, better on gas, but is not as efficient at high rpm's as the stock at higher rpm's as the clutch fan at cooling

Mechanical_stig
07-22-2018, 10:37 PM
No battery issues or alternator problems