General Tech Simple wiring kit for Taurus fan?

[Hickey]

I'm looking for the most simple and dead reliable way to replace my mechanical fan on my CJ5 with a Taurus fan. I already have the fan, I just need a plan to wire it. I do not want a thermostat, just want it to come on at low speed with the ignition on.

Electrical is something I really struggle with. I can make good clean connections, but that's about where my confidence ends.

 

[Kevin B.]

So you need a source of keyed power. If you have a fuse box under the hood you might find one there, or you might have to run it from the cab. You can splice into the wire or use a fuse tap. Depending on what sort of amps the fan draws, it might be a good idea to run that power wire to a relay that switches power straight from the battery like this:

The wire on 86 would be from your 12v ignition source, 85 is a ground wire. 30 is a power wire from battery +, and 87 goes to the fan (and then you have another ground wire on the other side of the fan). That's a pic of a five post relay, you'd ignore the center post or just get a four post relay that doesn't have one.

 

[TurboMinivan]

Control it via a simple relay. The relay's spades are numbered. Connect each as follows:

30: connect direct to battery + via a heavy wire. Place an inline fuse right next to the battery connection.
87: connect to the fan's low-speed power wire.
86: connect via a small wire to any convenient ground.
85: connect via a small wire to any 12v source which is only hot when the key is on (such as from the fuse box).

Wires 85 and 86 can be small because they only need to trip the relay (which requires hardly any amperage at all). Wires 87 and 30 need to be beefy because they are carrying the current to power the fan. But that's all there is to it.

EDIT (due to Kevin's post): for wires 85 and 86, it doesn't matter which one is the positive input and which one is the ground. It will work fine either way.

 

[Herzog]

I've used a Continuous Solenoid because the start up draw on the fan is quite high, but once it gets up to speed it doesn't draw much. I'm sure it's overkill but I've ran a solenoid like this since buggy version 1.

Grounded Continuous Solenoid Switch - SPST, 12V 100A

12 volt, DC solenoid switch is grounded continuous and ideal for heavy duty applications like a motor on-off control, winches, snow plows and other heavy electric motor applications.

www.delcity.net

You basically run your hot line through the two large poles there, the smaller pole is your open/close switch positive pole. This one grounds through the chassis so you don't have to run a ground for your switching pole.

This takes the place of the relay. With this, you just run a switch (in your case the ignition power on) to the solenoid and it will kick the fan on.

 

[Hickey]

I'm told that the Taurus pulls something like 80-85 amps on startup. Do I need a larger relay?

 

[TurboMinivan]

If you do end up needing to use the fuse box for the low-power trigger wire, my favorite method to do so is via an "Add-A-Circuit" fuse adapter. It is clean, elegant way to do exactly this. (I would link a picture, but I'm on my iPad which is a pain in the patoot do do things like that. Sorry.)

 

[TurboMinivan]

I'm told that the Taurus pulls something like 80-85 amps on startup. Do I need a larger relay?

Untrue, at least based on my own experience. I used to run a Taurus fan on my Grand Prix, and I set it up for low-speed operation only just as you plan to do. I controlled it via a single relay, and its main power wire from the battery had only a 30amp fuse. That fuse never blew.

 

[Hickey]

Untrue, at least based on my own experience. I used to run a Taurus fan on my Grand Prix, and I set it up for low-speed operation only just as you plan to do. I controlled it via a single relay, and its main power wire from the battery had only a 30amp fuse. That fuse never blew.

What size wire should I use to connect the battery to the relay or selenoid?

 

[Unimog]

Assuming the wiring is less than 10 feet, I would just use 10g and a 30A fuse.

 

[TurboMinivan]

Assuming the wiring is less than 10 feet, I would just use 10g and a 30A fuse.

That is exactly how I did it.

 

[Kevin B.]

EDIT (due to Kevin's post): for wires 85 and 86, it doesn't matter which one is the positive input and which one is the ground. It will work fine either way.

Right. I should have said, it doesn't really matter as long as you remember that 85 and 86 are for the trigger wire and 87 and 30 are for the power wire. It doesn't matter which way it goes through the relay.

What size wire should I use to connect the battery to the relay or selenoid?

Depends on your amp draw and the distance. Here's a chart: http://wiresizecalculator.net/wiresizechart.htm. You don't really need to worry too much about the startup draw, that's momentary and not really long enough to melt a wire (although you do want to fuse correctly for it or you'll blow the fuse every time you fire it up). Do you have a multimeter? I'd hook up the fan to a battery and measure the amp draw on startup and while running yourself and know exactly what you're working with.

 

[mbryson]

The high side of the Taurus/Mark VII/Windstar etc fans are the huge draw.

 

[spaggyroe]

I ran a MK VIII fan, high side only, using the continuous duty solenoid that @Herzog referenced. Worked great and dead easy to connect.

 

[MikeGyver]

Here's what I'm running on my wrangler.
My fan was dying so I got a new one from the junk yard.
I also saw this module and knew it was a PWM controller and how to hook it up. So I test it in the junkyard and sure enough it handles the fans 70+ amp startup draw (60 amp running) just fine.

If any of you need a high current solid state relay for on/off or PWM, look for a late 90’s Ford/Lincoln. It’s mounted right in the middle, on top behind the radiator... all you have to do is ground the signal wire.

It’s an active suspension (ABS / air ride compressor) relay, it has nothing to do with the fan so it might not be a commonly known about part, a quick internet search turned up nothing on it.



Here’s the part number. Cheap on ebay.
Pinout is (in the order shown in pic): battery +, motor +, ground, signal (gnd to turn on)

 

[spaggyroe]

Here's what I'm running on my wrangler.
My fan was dying so I got a new one from the junk yard.
I also saw this module and knew it was a PWM controller and how to hook it up. So I test it in the junkyard and sure enough it handles the fans 70+ amp startup draw (60 amp running) just fine.

If any of you need a high current solid state relay for on/off or PWM, look for a late 90’s Ford/Lincoln. It’s mounted right in the middle, on top behind the radiator... all you have to do is ground the signal wire.

It’s an active suspension (ABS / air ride compressor) relay, it has nothing to do with the fan so it might not be a commonly known about part, a quick internet search turned up nothing on it.

View attachment 133530

Here’s the part number. Cheap on ebay.
Pinout is (in the order shown in pic): battery +, motor +, ground, signal (gnd to turn on)

Good info.
Any idea what sort of input it’d require for PWM use?

 

[MikeGyver]

it's just a digital on/off solid state relay. You can give it a PWM signal, or just use a switch.

 

[Jay5.9L]

I have a 2 contour and a Derale PWM controller in my CJ. Works great! I have a whole thread about it on here somewhere

 

[Jay5.9L]

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[Jay5.9L]

The controller was on the expensive side but it’s been great.

 

[Pile of parts]

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