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simple dual-electric fan setup

it may not be the best setup BUT it sure beats the OEM setup

I mean when I used the OEM clutch fan my XJ NEVER went below 210, and if I sat with the A/C on it would start to creep up... then I would have to open the hood

each system has it's draw backs...

I think it might be a good idea to tie the OEM A/C fan into this setup?

maybe couple this with a 180 thermostat?
 
Only way I would want to buy a new OEM fan for this conversion is if it was the one made by motorcraft not by dorman or one of the aftermarket companies. If you look at the big taurus fan that most swap its over $300 bones for a new motorcraft one, dorman is like $90...... somethings a little off here.

I plan on a swap using a DCC controller and mayb a large taurus fan but yours seems a bit easier to fit compared to the huge taurus fan. I have a CSF 3 core radiator also which i believe might make it harder to fit that large fan without moving the radiator posts forward. How much distance is between the nearest pully and the efan?
 
yeah, only problem with that is that it will NOT be an OEM part... and as such it might not perform as well as the original, and might not last as long

either way you have to drill holes in the fan to mount it, SO there goes your warranty

further more the OEM fan has a Bosch motor powering the fan... the after market will not

I hope it works well for you

The additional electric fan is a great alternative to the mechanical fan, but the project will be on hold until I can do some more parts research....
 
I finished my install...

Running an OEM Toyota Corolla relay box through a BMW coolant switch so it's fully autonomous. I got the idea from a Toyota site, using a factory 4-Runner aux cooling fan relay box (uses slip brackets on the factory fuse box) I went with the Corolla because there were many more in the yard, and it housed 3 relays and a fuse assembly, not the 2 + fuse in the 4-Runner box... and the Corolla uses bolts to mount it.

The Corolla box has provision for 1x SPDT or DPST (5-pin Bosch style) and 2x SPST relays (just like a standard SPDT relay but without the center 87a blade). Toyota uses propitiatory SPST relays that have a large square plastic center "pin" to mate to the box. Other than that pin, the blades are in the same pattern as a standard Bosch unit. I chose to use the Toyota units because a handful tossed in the tool box at the JY cost me nothing. IF you would like to convert this box to use Bosch style in those positions, simply find yourself two more Corolla's, pull the 5-pin relay out, reach in with your needle-nosed pliers and pull out the yellow plastic spacer. Use these spacers in place of the propitiatory ones in your box. The two SPST slots are missing a provision for the center blade, so you would have to run the SPDT Bosch relay in a SPST format.... but they will fit, and will function.

I fabricated a small aluminum bracket which mounts the box to the two-hole tab between the XJ fuse/relay box and coolant overflow.

In the box below I have, from left to right... Bosch DPST actuating my HID Hella 500's, OEM Toyota SPST actuating my Taurus fan, spare OEM Toyota SPST (can be wired when I have something to wire to it), 30a fuse assembly which isolates both fan and light circuits. 12v power has been run directly to the (+) post on the front of the XJ fuse/relay box, with individual grounds run through ring terminals to factory grounding points.

2011-10-09171010.jpg




I took a 1/4FPT to 3/8MPT adapter, gigged it into my drill press, and ran a 1/2" bit through, just knocking the female threads out of it. I then ran my trusty 14x1.5 tap through the smoothed opening, and mounted my BMW switch there. Only the slightest amount of material was removed during the process, but I will keep an eye for cracks. There is 100% thread engagement on the temp switch, and I used a brass washer, not the aluminum that came with the sensor. I then used 3/8npt fittings from the hardware store to plumb it all into the coolant track. All junctions were sealed with T-tape, but I may adjust locations if this doesn't work well.



I found that by running a charge through both (+) leads on the fan allowed it to spin just a bit faster, so I ran 10ga wire to the fan, where it split to 2x14ga at the pigtail I took out of the donor car.

Here is the clearance with the YJ bracket. Since there is no longer the XJ cooling fan pully there, I have plenty of room with this install.

2011-10-05121223.jpg


One word of advice...

When locating your hole locations for the SS spacers, remember to leave excess room between the shroud and the fan itself. My first attempt caused rubbing, and I had to start from scratch.

Thanks again to the OP for the GREAT idea, I will be doing another set-up in the next few weeks on a friend's XJ.
 
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EHALL sorry to revive such and old thread but can you explain what was bad about the other switches you tried before settling on the BMW on? I can find tons of temp sending unit/fan switch premade enclosures but not a single one with a thread pitch to match the BMW one. Think about finding one with similar specs.
 
I'm forgetting to keep this thread updated

I found a 38mm hose adapter on ebay that fits the upper radiator hose well, and it either had a 1/4 NPT tap already or I was able to enlarge it myself to fit the temperature switch (don't recall). This was a couple of years ago, so no link sorry.

38mm_Adapter_Installed.sized.jpg


I just recently converted the Taurus fan to a 16" SPAL that I bought from Summit. The SPAL is larger diameter with more blades and much more power draw on the motor (I had to use a 40-amp fuse because the 30-amp fuses were blowing when the fan would startup). The SPAL fits inside the shroud, but I had to remove the finger guards at the top of the shroud and fabricate a little aluminum plate to close off the top.

SPAL_shroud_front.sized.jpg


SPAL_shroud_rear.sized.jpg


SPAL_fan_installed.sized.jpg


SPAL_fan_side_view.sized.jpg


I have been having issues with temperature creep on the highway for the past couple of years. I don't think its the fan but rather its all the added weight (over 5k lbs on the Jeep now) and equipment blocking the airflow. Just reporting for disclosure purposes.
 
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I went through all that years ago, as my 95 4.0 used to suffer terrible overheating issues. Even with hood vents, ceramic coated headers, all new cooling system, flush etc..

I had triple electrics and a separate tranny cooler all on switches etc. She still used to get hot and the noise of four fans spinning at full speed was intrusive.

I ripped the whole lot out about a year ago and put Hayden ZJ clutch fan in and a genuine XJ electric aux fan. Made sure it was all working ok and that the aux fan would switch on and off.
All of a sudden, the temp never got over about 190. I have an engine watchdog attached, so I get an accurate digital display of the engine and tranny temps. I also have an MT2500 obd1 scanner so I can see engine performance and open/closed loop status. I’ve also got a digital obd1 fuel economy display that gives me real time fuel usage at idle. I monitor all the systems to see how she is performing.

Anyway, the ZJ fan was loud, and it affected fuel economy, but worked great. I then swapped the mechanical clutch out for a new Hayden XJ clutch fan. Much quieter and better fuel economy. The temps went up slightly, but ive never seen the gauge go over about half way, with my digital watchdog readout at about 205. I’ve never been happier and consider the problem fixed on my Jeep.

Everyone is different, but I had 10 years of overheating before I went back to a brand new mechanical set up.

On a side note, with all the read outs I have, I’ve noticed closed loop comes on a lot earlier than folk sometimes believe. About 120f and she’s in closed loop. But my idle fuel gallons/hour keeps dropping and improving until the engine warms up to about 180. At 180, she is burning fuel at the most efficient rate. Any hotter makes no difference.

My XJ has a winch in front of the grill and I’ve also got a lot of accessories. I went to a weigh bridge and my XJ has added 1000lb of fat. However, she used to overheat when she was stock.

I’m not bagging the electrical setups, but just giving what I experienced.

I’m in Australia, and it gets pretty hot here too.

Cheers,
 
Mech fan isn't an option for me, I need to be able to turn the fans off and on for the stuff I do with it. I didn't have any issues until I started to really build it. I still don't have any issues on the trails, only on the highway.
 
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