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My Electric Fan Swap

61K views 114 replies 26 participants last post by  predatorbass 
#1 ·
The electric fan died on my Jeep a couple of weeks ago.. I plan to replace it with a Ford Contour fan that came out of a 1996 model. Once ordered, it came to my attention that these fans new or used rarely come with any wiring.

So here goes... Here is the old fan that came with my Jeep. Might be a Taurus. I do not know.


Here is my new (used) Contour fan minus the wiring.
Note the factory plug that came with it, Hackfab says these are pricey!
Look at all that room!
Here is a test fit, looks good. I do not even know if the radiator came out of a CJ or something else.

I will keep you guys posted on the progress.
 
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#43 ·
Thanks Cutlass, I am up and running with the dual contours... I feel bad for not updating this thread. I got the harness from rdsk8ter plugged it into the fans and resistor, one to power, and one to the thermostat and grounded it.

Works great, both of the fans kick on around 190 and cools it right down. I can actually feel the warm air on my legs when the fans come on. I must have a hole in the firewall that I forget to cover up with my "peel and seal" (cheap dynomat)

I need to change the wiring a little, the hot wire is not connected to a hot on the ignition, so the fans cycle on and a couple of times after the motor is shut off. I also do not like starting it with the motor hot, sometimes the fans are on while starting.

I will post some pics tomorrow.
 
#47 ·
#48 ·
Did you put some sort of reinforcement plate on the front of the WP pulley after you took the fan off? I had one on a donor engine for my Ranger - Turbo Coupes use electric fans. I imagine the flexing of the pulley could allow it to crack, and a dummy fan mount base would help support it for less flexing.
 
#49 ·
Did my first Highway trip with the Jeep today. Did a one hour highway trip. So far only rode around the hood....

On the highway it ran hotter! I guess because I was keeping up with traffic (around 70) temps were at 200. Exit the freeway and stop and go traffic and temps are at 180-190. What's up with that?
 
#50 ·
Those large areas of the fan shroud where there really isn't anything is blocking your flow. I've seen some OEM fans that had those areas like that only they were cut out and flaps of rubber put on the back of the shroud. This allows air to blow the flaps open if need be, but the fans will pull them closed when at lower speeds. This will allow more airflow at highway speeds.
 
#55 ·
THANKS FOR ALL THE DIAGRAMS! Now, what parts and how can I incorporate a soft start for these fans? Thanks in advance for responses and a lift of the lynch lid !

Gus
 
#56 ·
All you need are two standard 30/40A relays. I picked up a relay box with the cover from a salvage yard for $5.



This one has three main relays and 2 mini relays. You can use one for each fan and still have three left over for fog lamps, headlamps, high beams, etc.,.



As far as a soft start, you can't do that with that style of controller. You can achieve the same effect as a soft start if you wire in a capacitor in the circuit just like you would for a big stereo amplifier. I didn't bother with the capacitor as the momentary dip in my volt gauge is not a big deal to me and even helps me to see when the fans are turning on and off while driving down the road when you can't hear them.
 
#57 ·
Thanks so much for your speedy respone Coiz! :D You da Man!
Perhaps I'm being too cautious or it's the inner anal Marine in me but I've read in a magazine a while back and a few posts here and there that as far as the fan motors were concerned the instant on was hard on 'em so soft start was a good feature. Also it occurrs that since I'd be wiring in relays for protection of the control wiring and this entire procedure is intended to protect against overheating, it follows in my mind to take the protection all the way. :shhh: I guess now you know how my mind works!
Only now learing how capacitors work in this situation, if a line carrying DC voltage has ripples or spikes in it, a big capacitor can even out the voltage by absorbing the peaks and filling in the valleys. IF this is so and the capacitor eventually discharges wouldn't it dump it's charge once it reaches capacity? (Like bang goes the wiring?) Would that capacitor wire in between the relays and the fans, or before the relays?
Sorry for all the ameteurish questions, I'm no one's electrician.
 
#58 ·
Any of you guys know how to take 3 relays and make a Low to High step up relay system? I am going to run a mkVIII fan and would like it to come on at 170ish and turn to high at 195. But that set-up requires a step up, as high draws a ton of voltage at first. Not sure if this is the right place to ask.

Thanks
 
#61 ·
Any of you guys know how to take 3 relays and make a Low to High step up relay system? I am going to run a mkVIII fan and would like it to come on at 170ish and turn to high at 195. But that set-up requires a step up, as high draws a ton of voltage at first. Not sure if this is the right place to ask.

Thanks
You can do what you want with only two relays and one resistor much like the stock Contour wiring above. The low speed relay gets grounded with your ~170* coolant switch and the fan gets powered through the resistor to medium speed. The high speed relay gets grounded with a separate ~195* coolant switch and power flows directly to the fan with no resistor for high speed. It does not matter if they are both grounded at the same time because the electricity will always find the least resistance to ground and run the fan on high.

I could draw you a diagram if I had too.

:eek: Where's that icon for slapping my forehead?

Only NOW do I get it! That resistor (R27) on the shroud provides the slow speed and I don't imagine that's going to jolt the fan motors as I feared! So just a pair of 30/40 or 70 amp relay ahead of the whole shooting match should do the trick then! whew! ....unless I'm wrong again !
You're right that the resistor in the shroud is what creates the medium speed fans. It is in the shroud for a reason because it needs to get cooled by the airflow from the fan. I actually have mine wired to where they both turn on/off at the same time, but one is medium speed and the other is high speed.

If you want to use the stock resistor and have them both run at medium then high speed, wire it just like the Contour diagram but instead of the PCM it will be two different coolant temperature switches just like I described above. You can wire in a ground switch on the higher temp relay as a quick override for high speed fans too.
 
#59 ·
:eek: Where's that icon for slapping my forehead?

Only NOW do I get it! That resistor (R27) on the shroud provides the slow speed and I don't imagine that's going to jolt the fan motors as I feared! So just a pair of 30/40 or 70 amp relay ahead of the whole shooting match should do the trick then! whew! ....unless I'm wrong again !

 
#60 ·
BTW this fan cleaned up really well using De-solv-it and some ArmorAll

Before;


and after;



...not that I'm building some trailer queen
 
#62 ·
So I was planning to do this swap, and picked up a contour fan at the junkyard. Was an opportunity as it was already removed from the car. I have just finished my MpFI swap so I have a 93 Cherokee harness. It has relay and wiring provisions for a fan, as well as a temp sensor Wonder of it will suffice to operate the fan?

Also, Ned, where did you get all that room? Mine is very tight between the radiator and pulley. And it's a stock radiator. Doing some test fitting I don't think the fan will fit, even with mods.
 
#63 ·
:) Thanks so much for your patience Mike, I was overthinking this setup and, as I already have one temperature switch wired in, I understand the dynamics. Wiring in a second on should prove simple to me now. Geez, how did I make Sgt. in the Marines with my limited intelligence? (Luckily I got out before I made E-6, the "rockers" under the stripes, we used to joke, symbolizes yer brains going to yer @ss.) :D
 
#64 ·
One more thing Mike (sorry) & all, I saw a post on another forum where the Jeeper installed that diode on a jumper between the + and - poles at [C 1859] of the fan motor,



explaining that with the fans off that diode will prevent the fan blades from reverse winding of the electric motors preventing damage. Is this so and is this the proper location to place that diode?

Also, here's a pic of the resistor on the '89 Merc Mystique fan I have. (a little different than the dual strip kind I've seem elsewhere)



 
#65 ·
Okay gang, after being frustrated by failed attempts at getting part nos. I decided to go back to the boneyard and found these;

The text on the green one reads;
Ford C8F6A
93B6 8C616 AA
RELAT ASY.
ENG. COOL.
FAN CONTR.
12V-
[PA6-G30



The text on the normal sized one reads;
FORD G1UHD
93BG 14N089 CA
V23136-J4-X1

12V 70A

PA


Can anyone tell me if these are correct and what's up with the oversized green one?
 
#66 ·
So, using Mike's posted Contour diagram are these the relays?
Are these relays the correct ones as shown in that diagram (K46 & K45)?



Friggen Ford Dealership can't tell me on account of Ford's two year (in some cases) obsolesence procedure.
 
#67 ·
Went back to the boneyard looking for a bank of relay sockets (small footprint) and I found two more 70/80 amp relays for free with a more contemporary number;





I scanned several vehicles for small footprint relay pods, but so far those that take Bosch style relays are 6x9" and larger.
 
#68 ·
Sorry for my incessant posts folks, I will desist.
 
#70 ·
Thanks Cutlass, I just got too enthusiatic and posted that close up of that relay across too many threads that made me a nuisance to some. I'm going to be much more responsible now.
 
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