Electric fan and wiring question

[Todd]

I added an aftermarket fan when I put on my turbo kit. I ended up wiring it in to be turned on all the time with key just as a temporary fix until I figured out the wiring on the factory setup.

I originally thought I could just use the black and red (IIRC) off that silver module on the factory shroud. I thought that should correspond to power and ground.

However when I tested the wires it seems that they both have power instead of one being ground.


Can anyone help me on what that silver module is???

What are the 3 wires coming into the plug the module plugs into???

And what is the best way to wire in an electric fan to allow the computer to control when it is on etc....????


Thanks guys.

[FordNut]

I added an aftermarket fan when I put on my turbo kit. I ended up wiring it in to be turned on all the time with key just as a temporary fix until I figured out the wiring on the factory setup.

I originally thought I could just use the black and red (IIRC) off that silver module on the factory shroud. I thought that should correspond to power and ground.

However when I tested the wires it seems that they both have power instead of one being ground.


Can anyone help me on what that silver module is???

What are the 3 wires coming into the plug the module plugs into???

And what is the best way to wire in an electric fan to allow the computer to control when it is on etc....????


Thanks guys.
The factory fan is a variable speed computer controlled fan and the control signal is a PWM signal from the PCM. Like the alternator/regulator control signal and the fuel pump control signal. One of the things that makes it so hard to try stuff that works on Mustangs and Cobras.

It is possible that you could wire the aftermarket fan motor to the silver box just as the OEM fan was and it would work as a variable speed fan. Hook it up and turn on the AC to find out.

Another option is to wire a temperature switch in series with the fan power, leave the power source connected to switched power as it is, and attach the temperature switch to the radiator or engine. It would probably be necessar to have the switch control a relay so the motor start current wouldn't burn up the switch.

[Todd]

The factory fan is a variable speed computer controlled fan and the control signal is a PWM signal from the PCM. Like the alternator/regulator control signal and the fuel pump control signal. One of the things that makes it so hard to try stuff that works on Mustangs and Cobras.

It is possible that you could wire the aftermarket fan motor to the silver box just as the OEM fan was and it would work as a variable speed fan. Hook it up and turn on the AC to find out.

Another option is to wire a temperature switch in series with the fan power, leave the power source connected to switched power as it is, and attach the temperature switch to the radiator or engine. It would probably be necessar to have the switch control a relay so the motor start current wouldn't burn up the switch.

What is PWM?

[FordNut]

What is PWM?
Pulse Width Modulated

Turns on and off the 12 volt signal at a rate proportional to how fast the fan is supposed to turn. It's not the same as a variable voltage but has a similar effect. A variable voltage would cause the current draw to increase significantly. A PWM signal is still 12 volts so the current draw does not increase, it simply turns on and off a lot.

[Dennis Reinhart]

I added an aftermarket fan when I put on my turbo kit. I ended up wiring it in to be turned on all the time with key just as a temporary fix until I figured out the wiring on the factory setup.

I originally thought I could just use the black and red (IIRC) off that silver module on the factory shroud. I thought that should correspond to power and ground.

However when I tested the wires it seems that they both have power instead of one being ground.


Can anyone help me on what that silver module is???

What are the 3 wires coming into the plug the module plugs into???

And what is the best way to wire in an electric fan to allow the computer to control when it is on etc....????


Thanks guys.

The fan on a Maruader is a variable speed fan contolled by the VCRM this is dependent on water temp as well as AC head preasure.

Mustangs have a CCRM and these are two speed fans, what would have been best was to have used the VCRM wiring with the control off the OEM fan motor wired into your after market fans

[FordNut]

The fan on a Maruader is a variable speed fan contolled by the VCRM this is dependent on water temp as well as AC head preasure.

Mustangs have a CCRM and these are two speed fans, what would have been best was to have used the VCRM wiring with the control off the OEM fan motor wired into your after market fans
Sounds like a confirmation that the wires that hooked to the OEM fan from the silver module would be the place to connect the new aftermarket fan.

[Todd]

Sounds like a confirmation that the wires that hooked to the OEM fan from the silver module would be the place to connect the new aftermarket fan.


That is exactly what I tried to do....


But after checking the wires coming out of the module it appeared to have power out of BOTH wires...

And it appeard to have power after the key was shut off. I do not remember my fan running after the key was turned off.

But I didnt check this myself.. A ASE mechanic did while I was in the car turning the key on and off. So I may plug the module back in and test it myself.

Thanks for all the info. I will post back my results.

I really hope this works and maybe his results were wrong.

[TooManyFords]

I'm getting ready to put a custom radiator fan kit in this weekend. Was there any more info on this sort of thing? I need somthing simple and complete in the form of instructions...

It looks like I should re-use the silver box with the three wires from the loom. Should I cut the wires going to the motor? If so, how do I wire this up to my twin 11" fans?

Need some help here!

John

[FordNut]

I'm getting ready to put a custom radiator fan kit in this weekend. Was there any more info on this sort of thing? I need somthing simple and complete in the form of instructions...

It looks like I should re-use the silver box with the three wires from the loom. Should I cut the wires going to the motor? If so, how do I wire this up to my twin 11" fans?

Need some help here!

John

Here's what I would do if I were you...
Check out Summit, get a fan temperature switch from Painless, Flex-A-Lite, Derale, or others. They have a thermostat which can be setup to measure the coolant temperature and turn on/off at specific temperatures. There is also an adjustable version.

I'm not sure the OEM fan controller box will run a standard motor properly in place of the OEM one which is designed to be a variable speed motor.

[magindat]

Here's what I would do if I were you...
Check out Summit, get a fan temperature switch from Painless, Flex-A-Lite, Derale, or others. They have a thermostat which can be setup to measure the coolant temperature and turn on/off at specific temperatures. There is also an adjustable version.

I'm not sure the OEM fan controller box will run a standard motor properly in place of the OEM one which is designed to be a variable speed motor.

You, sir are correct.

Pulse Width Modulation turns the 12V on and off and switches it back and forth on the wires to the motor thousands of times a second. This will show a voltmeter a constant lower voltage because the switching is faster than the voltmeter can react. The signal going to the box is digital info from the ECM. The module converts this info to a PWM signal.

As such, a PWM motor must be used. a standard motor may run, but will burn up quickly.

The easiest way around is the 'old school' solution listed above. A more advanced solution might be to extract the stock fan motor and fix it to the new housing.

For TMF with dual fans, I'd seggest a fairly low temp temperature switch. Wire ground of fans directly to ground and send the positive through the temp switch. Low temp to assure fans come on before a problem. Similarly, you could run 2 temp switches one of higher temp than the other. Run one fan's positive to the lower and one to the higher temp switch. This would produce the effect of a 2 speed fan.

Summary: unless you can find a fan with a compatible PWM motor, go old school with a temp switch.

FWIW, Rich

[TooManyFords]

Thanks.

I had one of these on my F150 and completely forgot about it! (that's how well it worked)

http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX%2D31165&N=700+4294860934+115&autoview=sku

So I think I'll just get one of these to run the new Griffin fans.

It was programmable and runs the aftermarket fans between 60% and 100% depending on temp. I still ordered the relay kit from Griffin to interface the two...

Another busy day of wiring ahead I guess...

John.

[Drock96Marquis]

I can PM you the wiring diagram of your stock fan circuitry, and your replacement unit from another Ford model if you would like. PM me if you need them.

[juno]

Interesting, I had planned on just wiring my module to the new fans.

[TooManyFords]

I went and ordered the Flex-a-lite control unit so I'm just going to hide the existing connector. The FL controller also has controls to override for continuous ON etc. Like in the pits... Maybe this winter I'll add a Mezier water pump to take advantage of this.

Cheers!

John