E-fan Swap

Hello all,

I went to a pick-and-pull yard yesterday and was lucky enough to find and remove a fan from a 3.8l Taurus, unsure of the year. It is the 2 speed electric fan, I know that much for sure.

I hooked it up on my bench and both speeds work properly, no weird noises or any hesitation at all. Before I delve farther into this project I have a few questions I would like to ask.

1) What is the best fan controller kit? I have seen some with a probe for the radiator and I have seen some with a 3/8 NPT screw in temperature probe (which I am guessing goes into the block itself).

2) if I were to buy one of the fan controller kits with the 3/8 NPT screw, what else would I have to buy? I am guessing there is no simple spot to put it on these 5.7 TBI motors?

3) What temp should I have the fan kick on at? Should I even bother with an adjustable fan controller, or just buy one that comes out of the box with a set temp?

4) Which speed should I have the fan be powered on by? The 2nd speed on the fan itself seems to blow considerably faster than the 1st speed, should I just run power to that?

5) Should I hook the fan up to the existing fan shroud on the truck? Or make some custom brackets to clean the engine bay up?

Thank you for the help. I have read numerous threads on this forum already discussing this subject, however, these questions were either left unanswered or unclear. I apologize if anyone feels as if they are repeating themselves, but I am simply trying to get this done in the easiest way possible.


For anyone curious, the truck is a 1992 K5 Blazer with the 5.7l TBI motor. Completely stock.

These are the three fan controller kits I was looking at

1) https://goo.gl/Vvxvkb

2) https://goo.gl/bq6xjT

3) https://goo.gl/0I00ka

I have used Flexalite on 3 different vehicles....the one I have now I believe the part # ends in a 65?.....Its adjustable, radiator probe, a/c hook-up AND the 'soft-start' feature,.....$110 range.....For me, it's tried and true

Also, Ive always used the ford 3.8 and currently a 4.6 fan and shroud.....Surrounded by my factory top shroud

From what I gather, after looking into a Dakota Digital fan control, it appears as though they can utilize existing one wire temperature sending units. It also appears as though they will run dual speed fans.

http://www.dakotadigital.com/pdf/pac-2700.pdf
http://www.dakotadigital.com/pdf/pac-2750.pdf

....The PAC-2750 was designed for the ultimate in flexibility and to be a simple add-on in any application using an electric fan. Included is a 70amp relay, enough for even the most power hungry of cooling fans. Fully programmable, the PAC-2750 will work with your existing water temp gauge, operating from the temperature sending unit already installed. A dedicated sending unit can be installed for applications without a water temp gauge. OBD II compatible vehicles can obtain the engine temperature from the ECM with the use of a BIM-01-2 (or previous BIM-01-1), purchased separately.

When used in conjunction with BIM-compatible Dakota Digital instrumentation or a BIM-01-2, a single cable transfers speed and temperature data to the PAC-2750 allowing the fan to be shut off at an adjustable highway speed....

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=852/prd852.htm

Click to expand...

I am currently using a flex-a-lite variable speed controller, with the push in radiator probe and my air conditioning compressor is wired in. Right now I have em set to come on at about 204 F.



The reason I am checking out Dakota Digital is that I don't like the fact that at highway speeds my e-fans cycle on and off with the a/c compressor. For my OBD2 they seem to have http://www.dakotadigital.com/index....ct_id=752/category_id=-1/mode=prod/prd752.htm.

Have to wonder if there is a simpler/cheaper method of having the a/c-efan function disabled at highway speeds, like a relay wired in that would open the a/c compressor to efan circuit when the torque converter is applied / locked up(high speeds).

FWIW, l pull the a/c compressor fuse in the winter time, so that when I am using the defrost all day the efans arent constantly running, the fans still function when/if the coolant temp requires it and the defrost still clears the windshield.