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Electric Fan Conversion Install

kcox506

NAXJA Forum User
Location
Concord, NC
I wouldn't consider this a generic how-to given my situation is a bit different, but the concept is the same. This is for those who want to know a little more about what the electric fan conversion looks like.

Since I decided to be that guy and put an 06 TJ 4.0 in my XJ, I had to play with cooling options. My original idea was to keep the TJ setup, and run the mechanical fan with an aux fan. However, due to the lack of an efficient fan shroud and proper CFM, my first wheeling trip at the SEC crawl at Harlan KY was met with utter failure. Live and learn.

I grabbed a Dirtbound Offroad electric fan shroud and paired it with three electric fans I got from K Supsensions & Auto. Along with a complete fan controller harness.

I was concerned with the fitment on the shroud at first, since the bolt holes were clearly not the same on the fans to the shroud, but it all gave enough movement to make it work. I was able to successfully use the provided hardware from dirtbound to mount the fans.



The only shroud modification I had to make was to grind down a little bit of the bottom edge of the vertical reinforcement pieces to fit over the bottom lip of the radiator. Holes had to be drilled at the top of the shround to accept the provided brackets that grab the radiator support bracket thing.





The shroud with fans installed was relatively easy to fit. You will have to bend or cut off the bottom tabs that the original OEM fan shrouds mounted to. Mine were already cut off because of TJ things, but don't let that be a surprise.



Now comes the fun part. The wiring harness provided by K Suspensions, I will say is very well thought out. It may be "chinese" relays, but nonetheless very stout. I would recommend taking a hot glue gun and filling in the bottom of the relays and in-line fuse for better waterproofing. I was given an additional relay harness for the third fan that I did not end up using. However, it is perfectly ready to roll for an additional accessory, like a light bar, OBA compressor, etc. Its pretty nice to have that laying around for a future project.



The first thing I did was place the Temp Sensor. Its a prong that you stick into your radiator. Interesting approach to grabbing a core temp reading. Reminds me of my enlisted days lol. I am concerned on how loose it fits. I will have to go back and try and hot glue or silicone it in for a more secure fit (giggity).





The wiring is very simple. Run the orange wire to a fan, and the blue wire to a fan. If you are running dual fans like I did; its orange to fan 1, blue to fan 2. If you are not, ignore the blue and just run orange to a fan.



I then made a ground wire to grab both fan 1 and 2. This was not provided, I used my own wiring and connectors to make it happen.



The third fan I simply plugged into my stock Aux fan harness that was already spliced and and ready to roll from my previous setup. I have coming off the stock harness and on a fan override switch. It kicks on when the computer tells it to, or when I turn the switch on.



Now comes wiring in the controller. The controller can be adjusted from 160*F, to 250*F. It comes set to 160*F which is what makes sense to me. It takes a phillips screwdriver to adjust the setting on the back of the controller.



The Yellow wire needs to be connected to an ignition power source. Meaning that when you turn the key to ACC or start the vehicle, it will only then get power. I took a Multimeter to my PDC to find a wire that did just that. I believe I found the fuel pump relay wire (a solid blue wire which looks to be 10-12g) as my ignition source. There's a splice-in connector provided which I hate with a passion, so I opted for a waterproof buttend connector, because I'm normal.

(I had to extend the yellow wire, hence the red shown)


There is also a green wire that you splice into the A/C compressor to turn on when you turn the A/C on. I do not have A/C, so I do not care. I terminated it with what I had. Do as you wish.



Thats it. You're done. Turn Ignition on, test Fan 3. Start and let it climb to temperature and fans should kick on. They're loud and let you know they're there. If they are not kicking on, make sure the sensor is set to 160 and not 210 like mine was. I was chasing a wiring gremlin for 15 minutes until I realized mine was set correctly.

Test drive that bad boy and hopefully don't burn into a fiery pit of death.



Closing remarks:

This is the only correct way IMHO, to run an electric fan setup. If you do not have a fan shroud....you will not cycle in the air efficiently and you will die. If you do not have them relayed and fused, you will die.. Probably not, but it won't be 100% correct and you may have issues.

I believe its 1600 CFM across the radiator.

They're loud.

I did not use all of the provided pieces by either party.

It works..so far.

Here is the link to Dirtbound Offroad.
https://www.dirtboundoffroad.com

Here is the link to K Suspensions.
http://www.ksuspensionlifts.com
 
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How well do the 2 fans do by themselves? I have 2 stock e-fans currently and the one fan running on its own with the other still setup like stock, the Jeep creeps up to 215 at stop lights. When the other kicks on at 215 it comes back down and when moving its 200-210. I am really considering doing the triple fan setup at this point.
 
How well do the 2 fans do by themselves? I have 2 stock e-fans currently and the one fan running on its own with the other still setup like stock, the Jeep creeps up to 215 at stop lights. When the other kicks on at 215 it comes back down and when moving its 200-210. I am really considering doing the triple fan setup at this point.

It it stays a hair under 210 and doesn't move despite my aggressive driving. However, my results are skewed since my third fan is on full time at the moment. I haven't switched it back over to a switch yet. Currently have the ECM wire grounded out.
 
Nice write up.
 
It it stays a hair under 210 and doesn't move despite my aggressive driving. However, my results are skewed since my third fan is on full time at the moment. I haven't switched it back over to a switch yet. Currently have the ECM wire grounded out.

Nice to know. I would love to hear feed back of how just two fans full time handle the cooling. Like I said I would love to do this setup and leave the third fan, closest to the ECM, hooked to the OE fan circuit and functioning like the OE fan.
 
Did you say it was 1600 cfm across the radiator....or did you mean 1600 cfm per fan across the radiator.

^^^This. No way 1600 CFM would cool properly. 1600 x 3= 4800cfm should work nicely.
 
Nice to know. I would love to hear feed back of how just two fans full time handle the cooling. Like I said I would love to do this setup and leave the third fan, closest to the ECM, hooked to the OE fan circuit and functioning like the OE fan.

That's how my electric fan setup is. Two 10-blade OEM fans; one still controlled by the A/C ON switch or coolant temp sensor, and the other by a Spal PWM LO/HI speed controller. Each OEM fan pulls ~2250CFM at HI speed. Never had an overheating problem with this setup.

https://comancheclub.com/forums/topic/7895-dual-oem-aux-fan-installation/
 
That's how my electric fan setup is. Two 10-blade OEM fans; one still controlled by the A/C ON switch or coolant temp sensor, and the other by a Spal PWM LO/HI speed controller. Each OEM fan pulls ~2250CFM at HI speed. Never had an overheating problem with this setup.

https://comancheclub.com/forums/topic/7895-dual-oem-aux-fan-installation/

I have a dual-electric setup in mine as well, using a fan from a 3rd gen Taurus alongside the 10-blade XJ electric. I don't know the CFMs but they are more than capable of keeping the engine cool in my part of the country (not sure I'd try desert racing)

http://www.naxja.org/forum/showthread.php?t=1035194
 
Thank you for good job on the article.
I might add a few things.
There is really no point on running your fans blowing air thru the radiator with the thermostat closed.
Modern engines often have a higher than desireable thermostat.
You can get better results by lowering the thermostat to and letting the fan switch maintain your low speed temp.
So on the Highway you will be a little cooler running on the thermostat and at low speed you will get much more efficiency blowing across a full temp radiator.
 
Thank you for good job on the article.
I might add a few things.
There is really no point on running your fans blowing air thru the radiator with the thermostat closed.
Modern engines often have a higher than desireable thermostat.
You can get better results by lowering the thermostat to and letting the fan switch maintain your low speed temp.
So on the Highway you will be a little cooler running on the thermostat and at low speed you will get much more efficiency blowing across a full temp radiator.

I disagree........the water in the radiator will cool down so that when the t-stat does open, cold water goes into the block, not warm water.

That's the whole idea....t-stat closes, water in block heats up...water in radiator cools down....then t-stat opens, and they swap places and repeat.

t-stat temp...desirable for whom ?? it is set for economy & power, not just power.

Get more efficiency at what ?? cooling the hotter water down ?? at the expense of a hotter running engine ??

(His fan setup pulls air thru the radiator, it doesn't blow it across)


.
 
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What's the draw on the alt like? Do you now carry a spare e fan incase one shits the bed?


Sent from my iPhone using Tapatalk
 
What's the draw on the alt like? Do you now carry a spare e fan incase one shits the bed?


Sent from my iPhone using Tapatalk

lol no I do not carry a spare fan in case one dies. I would hope I wouldn't have to worry about one failing for quite sometime, given they are brand new. If one does, needless to say I will be investing in the highest quality I can find.

I do not know the draw on the alternator. I guess I can look into that sort of thing. I may make a video following up on a lot of questions I have been asked.
 
By your picture, they draw 6.6 amps(80w). That's how they're listed on ebay. I would question they're CFM's but since they're really cheap units I would definitely carry a spare!
 
By your picture, they draw 6.6 amps(80w). That's how they're listed on ebay. I would question they're CFM's but since they're really cheap units I would definitely carry a spare!

If I had one concern, it would be that they're cheap. I would vote for Spal fans.
 
It seems with electric fans it's always a tradeoff, and one very hard to achieve with 10" diameter fans... I have a couple of 12" SPAL fans that were bought for a different project and they are thick... would not fit anywhere that well even if I did fab up a shroud to make them fit onto the stock radiator... 10" fans that move a lot of air will still have a thick motor and are definitely gonna be $$$... To me it does make more sense than the mechanical fan though and I will probably do it sometime down the road. Did you do any alternator upgrades or is the 97+ alternator good enough? Any chance of easily wiring in an override on switch for the first two fans?
 
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