Hello folks. I am in the process of doing a dual electric fan install/conversion (Ford Windstar) on my 74 C-10 (No, not a Chevelle but.. the principles are the same). I have did an extensive search (here and elsewhere) and based largely on this post (http://www.chevelles.com/forums/showthread.php?p=2099631) (Thanks Bubba). But, before I burn down my garage I would like to reassure myself that I am doing it right. Here is what I would like to do.
1. Run the fans off of my battery.
2. Have a temp switch (threaded) and a manual toggle switch.
3. Maybe add a indicator LED light later.

Here is what I bought today.
1. (4) 30 amp relays.
2. (2) 30 amp fuse holders.
3. (2) 16ga fusible links.
4. 10 ft of 8ga,10ga and 14ga wire.
5. Assortment of connectors.
6. Heat schrink.

I don't really know if the fan assy. is a two speed or not. How do I tell? If so, how to I switch between low and high? If it is a two speed fan, is there an advantage to using two replay's for each fan (one on the high side and one on the low side)?

I have a stock alternator (probably 63 amp). I don't really have any other power draws, no power window, no electric fuel pump, no electric choke, no radio (that works), no interior light, nothing except headlights, brake lights, ect. and my CDI (Crane HI-6).

I have attached a pic of the wires coming from the fan.
I was really impressed on how well the schroud fit. I still have to do some more minor trimming, but for the most part she fits great.

If anyone could get me started on the wiring I would be greatful. I am an idiot when it comes to electrical stuff. Thank you in advance.

http://img.photobucket.com/albums/v208/Nolowrider/Picture008-1.jpg

http://img.photobucket.com/albums/v208/Nolowrider/Picture012-1.jpg

Hey Steve! I'm getting ready to do the same install on my 71. What I can tell you is that the green dot is the positive wire, other is ground

http://i15.photobucket.com/albums/a380/n3jhv/Stuff/P1010029.jpg



On the larger fan, same orientation; as in the picture below, positive is on the right, ground is on the left. For grins, I hooked up positive to the middle, got the same speed as on the right. Still looking to find out how to run it in 2 speed mode.

http://i15.photobucket.com/albums/a380/n3jhv/Stuff/P1010030.jpg

Thanks Sid fr the reply. Yea, the wiring thing is what I am concerned about. I don't want to burn my fans up, or God forbid my truck. Maybe we need some type of riostat to vary the voltage. Not sure. I have several schematics I found here and on the net that I will go by.

I do think I want to throw a diode in there (somewhere) to prevent any back current.

http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/foglites.htm

http://www.geocities.com/smithmonte/Auto/MarkVIII_Fan.htm

http://www.alanhorvath.com/54chevy/mad_electrical_2.php

I am sure together we will figure it out.

What year windstar are those fans from?

Perhaps---and I am not sure about this.
But if both of the positive pins get 12v it will speed up or slow down.

I would imagine that these things are computer controled (I have a Windstar and am totally clueless about it) with the 'puter activating the relays.

My former 94 T-Bird ----- the fans would come on when the temp sender was disconnected----weird

Windstar fans are controlled by the PCM through either a constant control relay module, (CCRM), or regular relays in the underhood junction block, depending on the year.
Either way, the low/high speed fan operation is managed through an external dropping resistor external to either the CCRM or regular relay system.
When on low speed, the relay with the dropping resistor in series is energized and the fans are powered through the dropping resistor. When on high speed, the high speed relay without a dropping resistor in series is energized and the fans are powered without any voltage drop. On the three pin connector pin1=gnd, pin2=not used, pin3=power. On the two pin connector pin1=gnd, pin2=power.
(EDIT) This is the Windstar circuit w/o the CCRM module.
http://www.chevelles.com/showroom/data/500/medium/05_Windstar_Fan_Diagram.jpg
Mike

What year windstar are those fans from?

Mine is a 98

Thanks Mike! Now I know the speed control is external, so I'll just run each fan on a switch to control how much cooling I need.

Mine is a 98

Mine is probably 98 or 99.

Thank you Mike. That makes sence. I just need to find a dropping resistor and wire it in. Any input on what size?

I see that you are in Detroit. Good place to be for you because you seem to know what you are talking about. Do you work in the auto industry? Thank you.


Wish I could fly you down here to install it for me. :yes:

Mine is probably 98 or 99.

Thank you Mike. That makes sence. I just need to find a dropping resistor and wire it in. Any input on what size?

I see that you are in Detroit. Good place to be for you because you seem to know what you are talking about. Do you work in the auto industry? Thank you.

Wish I could fly you down here to install it for me. :yes:

Thanks Steve, :)
Yes, I used to work in the auto industry, now I have my own business.
Using a resistor to control fan speed may be cheap but it's not a good way to do it. The best way is to use a PWM control circuit.
The real issue with making a multi-speed (discrete) fan controller, whether it uses a resistor or PWM controller to control the lower speed(s) is that you have to "calibrate" the resistor value(s) or PW duty cycle(s) to ensure the most efficient fan operation for each individual cooling system.
Optimally, for a two speed fan, you want your slow-speed fan operation to be able to maintain average engine operation temps. The only time you really want/need the high speed to come on is when the engine experiences severe operating temp conditions. So, for example, if you don't calibrate your fan "controller" and use a resistor value that is too high for your particular vehicle, (or a PWM value that is too low), the fan runs too slow and thus won't cool your engine under average conditions........resulting in the fan that almost always runs at high speed anyway. Conversely, if you use a resistor value that is too low, (or a PWM value that is too high), the fan will run very fast at "low-speed"......and will almost be running at high-speed again.
So you can see that there is more to just using the resistor value from a stock Windstar. Most likely, if you do, the fan will/needs to run at full speed most of the time whether you use an automatic fan control circuit or manually control the fans speeds. This is because the fan speeds for a stock Windstar were "calibrated" for use with an engine that creates a whole lot less heat than your car.
I bet your saying "blah blah blah, who cares. What's the best answer for MY CAR then?" In my opinion, the best solution that i've made for my car is a variable (non-discrete) PWM fan controller. As the temperature goes up, the fan controller ramps the PWM to the fans to control the engine temp at my adjustable temp.
For your car, I would just use the fans on single speed, controlled through the relay(s) by a Hypertech or Jet fan switch. These switches have an on-off (hysteresis) delay, which means they turn on at 195-200 degrees but don't turn off till the engine cools back to 185.
I don't know how many amps those fans draw so I can't tell you much more about the design of your fan system, such as whether you need to run one or two relays, what amperage it/they should be, wire size, fuse size/type or layout. Some fans I use only need one relay, some two, etc. You should hook up the fans to B+/gnd and check the draw to know exactly what you need. Also, make sure the relays you use have an internal diode to suppress the voltage spike when they turn off. These are not absolutely critical for your car but are a good practice anyway. If you do use them, be sure to know that they are polarized. Meaning the B+ and gnd connections have to go a particular way.
Most people don't wire their fans correctly, but with a little bit of work and number crunching it's not that difficult.
:thumbsup:
Mike

Thanks Steve, :)
...the best solution that i've made for my car is a variable (non-discrete) PWM fan controller. As the temperature goes up, the fan controller ramps the PWM to the fans to control the engine temp at my adjustable temp...

Hey Mike, What PWM controller are you using? Is it a "homebrew" of some sort, or do you have a model number you could throw my way?

Noah P.

Hey Mike, What PWM controller are you using? Is it a "homebrew" of some sort, or do you have a model number you could throw my way?

Noah P.

Hi Noah,
Yes, I am using a homemade PWM fan controller, integrated with the MPC55x of my homemade transmission controller.
I don't know if anybody makes an aftermarket PWM fan controller so you may have to use a standard analog fan controller if you wish to vary the speed of your fan........unless you are excited about learning about embedded control systems. In that case you will be able to make your own. :yes:
However, while a ramped PWM controlled fan works fantastic, it is not really necessary. Most fan systems do okay with simple one speed fan operation, activated by a temperature switch.
Sorry, I can't be of more help.
Mike

SPAL makes a PWM controller as do others.
http://www.spalusa.com/store/main.aspx?p=itemdetail&item=FAN-PWM-V3