fan controller question

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joshua dewitt

joshua dewitt

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running champion 3 core 26" radiator.... and a ford contour dual electric fan set up... looking into fan controllers for the heavy loads.. I know needs to be capable of 34-40 amps on each fan... looking into the Derele dual fan controller... or Ron Francis unit.. have any of you guys have any experiences with doing so? looking more for a pulse width modulated set up, instead of just on or off, will be a real high.low set up too. and I am running a 90-100 amp power master alternator...
 
I think the fans are just too high current for any type of PWM setup. I'm not sure why you think you need PWM. On the low speed the fans are pretty quiet. My high speed has never needed to turn on.

I'm running the Dakota Digital Fan controller as is 72blunblu. The reason why this setup works so well with these fans is that it's set to work with the dual speed fans and all the current is handled by the 70A relays, which makes it pretty simple and reliable. The controller just closes the relays through grounding, just like the factory contour computer did.
 
Seach on the H.A.M.B website. Most rodders running the Ford 2-spd fan use 2 or 3 mechanical relays. One guy sells a setup on ebay, I recall.

But if you really want solid-state control, I bought a fan relay ($25) for my 96 Voyager to possibly use on one of my A's. If not, it is just a spare part. Don't recall the rating, but it runs 2 fans so is probably at least 60 A rated. It needs a good heat sink and is riveted to the front bumper on minivans. I think it is a simple on-off transistor (not PWM). As I recall, one fan wire gets +12 V and the SSR shorts the other wire to gnd to run the fan. Similarly, on the input side, the engine computer shorts the control wire to turn it on. You can find a Voyager wiring diagram online to copy.
 


There's the wiring diagram. Other than that you just have to set it to be a dual speed fan and everything works well. I recommend 200 on/195 off for low speed and 210 on/205 off for high speed with a 185 thermostat.
 
I thought you had two fans, not a two speed fan.

If, in fact, you have a two speed fan, I ran across a simple set up that is working quite well for me on my truck. I am running the 2 speed Mark VIII fan controlled by a Volvo 2 speed relay that is actuated by a BMW dual thermo sender. I have about $50 into the control system. The BMW sender will send signal to turn fan on low when needed. If high speed is needed, the Volvo relay turns off low as the high speed comes on, essentially ramping it up without super high voltage spikes.

This is a link with a fairly complete run down on whats needed.
http://www.nastyz28.com/forum/archive/index.php/t-200028.html
 
He does have two fans, but they act as a single 2-speed fan, even as wired in a Contour. The contour has the diode/resistor pack for the low-speed. Both motors need to spin always, otherwise it's unlikely you'd get very good draw through the radiator itself. It's not a divided shroud.
 
Yup, Dakota Digital PAC 2750 here for me too with my contour fan set up. The contour set up has two fans with high and low speeds. Although just like goldduster318 I don't think my fans have ever gone to the high speed in actual use conditions.

Fans mounted on the Champion 26" 3 core
IMG_1558_zps3b79216a.jpg


Relays visible in the corner, wired into my continuous duty relay set up for my trunk mounted battery and cut-off switch.
IMG_1563_zpsdd343921.jpg
 
Does a fella have to upgrade alternators and all that to run an electric fan?
 
Bad Sport said:
Does a fella have to upgrade alternators and all that to run an electric fan?
Click to expand...

I did. I run a 100amp TuffStuff alternator on mine. From everything I've read the Contour fans pull about 30-35 amps at start up, then drop into the mid to low 20's for amps on low speed. .

You might be able to get away with the stock one if you never use all of your accessories at once, like if you only drive during the day, when it's warm, dry, etc and the fans are the only accessories using power. But on start up that's over half of your alternator output.

Of course, if you drive regularly on the street in all conditions the stock alternator doesn't have the juice to run the fans if they kick on when you're sitting at a light in the rain with your headlights, brakelights, wipers, heater, and stereo all going at the same time. Heck the stock alternator will barely do that without the fans.
 
Thanks, I am planning on doing the ammeter bypass, so at that point I assume I can upgrade the alternator.

Accessories? Lol, the only thing I have is lights and wipers. :D
 
Bad Sport said:
Thanks, I am planning on doing the ammeter bypass, so at that point I assume I can upgrade the alternator.

Accessories? Lol, the only thing I have is lights and wipers. :D
Click to expand...

I have a 78 amp Delco 12SI and it's *JUST* enough to keep everything bright with the lights, brake lights, fan, radio, and blower on at idle. And it charges much better than a Mopar alternator at idle. Probably going to need to upgrade with my EFI swap coming soon. The electric fuel pump is probably going to push me over the edge.
 
Bad Sport said:
Does a fella have to upgrade alternators and all that to run an electric fan?
Click to expand...
Two schools of thought on that. One is that if your battery stays charged over a week, then "good enough", since all components should work properly off battery voltage alone (12.6 V). That means your battery is discharging when all loads come on like radiator fans and recharging when they are off.

The other school would say for optimal operating (headlights at max brightness, ...), you want the alternator to power everything even at peak load, thus maintaining ~14.2 V always. If so, you need a bigger alternator and insure the output wires can handle it, or better bypass the ammeter & bulkhead by wiring it straight to BATT+ (MAD Bypass).
 
goldduster318 said:


There's the wiring diagram. Other than that you just have to set it to be a dual speed fan and everything works well. I recommend 200 on/195 off for low speed and 210 on/205 off for high speed with a 185 thermostat.
Click to expand...

I just bought the Dakota Digital controller for my Champion radiator w/dual fans. The instructions that come with it don't say anything about running the "low speed resister/diode" that you show? Is that something that is necessary when running the Contour fans?
 
BrianT said:
I just bought the Dakota Digital controller for my Champion radiator w/dual fans. The instructions that come with it don't say anything about running the "low speed resister/diode" that you show? Is that something that is necessary when running the Contour fans?
Click to expand...

Unless they are contour fans, you aren't going to have the resistor/diode for the dual speeds.
 
just finally got he time to wire the contour fans with the Dakota digital pac-2750 controller, awaiting a new fuse box via e-bay that I'm adding all the loads from, so no factory wiring over load on old wiring... all aftermarket add ons are wired independent of the factory. wired line the diagram sent to me on this trend. hope it all work out ok...., oh yeah since day off (vacation day) did all my running around, and even dropped by my fiends shop. and he sold me his old transmission jack the style for using a shop lift, for 50 bucks, and it works. sore for me today!!!!
 
I use the derale dual fan controller. The first one comes on at 185, the 2nd at 195.
 
goldduster318 said:
Contour_Fan_Wiring_zpsfc112fe5.jpg


There's the wiring diagram. Other than that you just have to set it to be a dual speed fan and everything works well. I recommend 200 on/195 off for low speed and 210 on/205 off for high speed with a 185 thermostat.
Click to expand...

goldduster318 I have a question about your wiring diagram, I think I have it wired correctly however now I’m second guessing my work

The wires on the fans labeled A and B which color is which? I have the blacks as A and the green wires as B but that isn’t how they are shown in your diagram b in your diagram would be black and A would be green. See my linked pic below
 
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I can't see your attachment but this is my diagram. Are you referring to at the fan connector? They could be any color really.
fanwiring.JPG
 
26B16891-4700-4A61-B751-E3C7C7F60533

The fan I have is one removed from a car in the junkyard with the wiring that came it’s it, I am confused by the a and b in your diagram, the wires on mine are a large gauge green wire and a smaller gauge black wire I am unsure of which one needs to go to the relay, I currently have it setup to send the green wires to the relay and the blacks to chassis ground.
 
A=1 and B=2 so black is ground and green is power.

Even if they were backwards it would just flow air the wrong way, so do the streamer test to be sure.
 
Resurrecting this to get an AC wiring answer. Thanks to Goldduster318 and 72blunblu, I'm installing the Countour fan setup with the PAC 2750 controller. Goldduster318's schematic shows the AC pin on the controller going to the AC clutch cycle switch. Where do you tie in? Do you splice into the wire under the hood that goes to the compressor? Or is it somewhere under the dash. Any help is much appreciated.
 
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