I would not wire the fans with anything under a 10 gauge wire.  A good fan draws 30+ amps at inrush and 22ish running.  A typical 16 gauge wire is going to get very hot and fail and maybe burn your ride to the ground.  You can get away with small gauge wires for a relay trigger or even a ground, but those fans are running directly off the battery once the relay is triggered.  I think the AutoCoolGuy setup doesn't use a relay, but its still putting out high amperage to the fans.  I think it uses FETs or something instead, but the wiring in principle is the same. 

The fans hit that load at start up not while running, correct me if I’m wrong.  The ACG controller is a slow start on the fans so it never sees the huge initial current draw you would normally see from a full on mode.  This is why the ACG controller does not need relays.  Even the ACG drawing has the fan power wires jumped between the two.  I’m no electrical expert but there has to be a reason for this.   Why I’m not sure but thought I should mention it. 

I’m attaching picture and you can clearly see the yellow wire I speak of is not 16g.  It looks more like it might be 10g?  You can see the difference in the stick wiring size.  The end with the eyelet is just the other end of the heavy gauge yellow wire which connects to the solenoid. 

John Ha wrote:

I will offer a caution about using the green/red wire as a trigger for the fan module.  That wire also has voltage when the key is in the "Accessory" position.  If you want power when only the ignition is powered (but not when the accessories are powered with the engine off), use the yellow wire that you used to bypass the pink wire.

 
I didn’t realize that.  Thanks for pointing that out.  Not sure why a wire to the voltage regulator would be hot  in the accessory position.   

The yellow wire is being used to supply 12V to the coil.  This yellow wire comes from the gauge and is suppose to connect in the pigtail in the photo, I have it folded under the connector holding it with my finger.  I do have an extra yellow wire from the blower motor that’s not used and has no power to it but I was thinking of using it to power the AC compressor.  With the CAA setup I don’t need either the brown or yellow going to the original blower motor.  I need to look but I think the brown only has power in the run position so maybe I could use it to power the fan controller?

Just be sure to label AND catalogue the changes you make using existing wires/colors/etc. That way once you've slept,,,,,,
(Or 20 years later)you will be able to sorta easily figger out what you did with this yellow...and this brown...ya know...?
(Zat sound like I have been down this road before ?!)
6sally6
Especially if you decide to hide all your under hood wiring some day to really clean up the look under hood...

RTM wrote:

I didn’t realize that. Thanks for pointing that out. ...  The yellow wire is being used to supply 12V to the coil.  This yellow wire comes from the gauge and is suppose to connect in the pigtail

If I understand things correctly, your controller has an "enable" signal that allows something inside to apply power (from another input to the controller) to the fans when the enable is powered.  You were going to use the green/red wire for the enable.  But since you really only want (I assume) the enable signal to be powered when the ignition is powered and not when the accessories alone are powered, you can tap into the yellow wire that you have used to bypass the pink wire.  The yellow wire power comes from the ignition switch (as does the power for the pink wire).

You could then provide the operating power for the fan to the controller with a dedicated, fused direct line to the battery.

That's probably as clear as mud but I don't know how to state it any more clearly - probably need more caffeine or something.

boss347convertible wrote:

I purchased the same controller and met Darryl. He is a great guy and walked me through the installation process and his manufacturing facility (garage). If I recall correctly, the connection No. 2 (ignition) turns the unit on. Connection No. 3 ( Battery) is the power source for the fan(s).

My recollection is that this is a soft start unit that does not draw high amperage upon start up, and depending on demand, doesn't typically operate the fans at maximum draw.

I will follow your endeavors and hopefully install my unit soon.

 
Hopefully mid to late September I’ll be ordering the controller and fan.

RTM wrote:

I’m getting confused with all the posts on this topic. 
However, based on this Auto Cool wiring diagram, you’ll need three ‘Battery” sources (Hot all the time); one to each fan, and one to the Auto Cool Controller.  I believe this will allow the fans to run with the ignition ‘off’, which allows for cooling the engine after shut down (if needed).
As the fans require a 40amp fuse/circuit breaker, I would run separate feeds to each fan and to the controller.  While this diagram doesn’t indicate a fuse/circuit breaker for the battery feed to the controller, I would believe that there should be one.
And you’ll need to one “ignition” feed to the controller.
 

BobE wrote:

I’m getting confused with all the posts on this topic. 
However, based on this Auto Cool wiring diagram, you’ll need three ‘Battery” sources (Hot all the time); one to each fan, and one to the Auto Cool Controller.  

No, there's only one battery supply and it goes to the controller terminal 1 ("Battery").  The controller outputs ("Fan A" and "Fan B") pulse-width-modulated power to each of the fans to run and vary the speed of the fans.

Last edited by John Ha (8/15/2024 9:24 AM)

BobE wrote:

John Ha wrote:

BobE wrote:

I’m getting confused with all the posts on this topic. 
However, based on this Auto Cool wiring diagram, you’ll need three ‘Battery” sources (Hot all the time); one to each fan, and one to the Auto Cool Controller.  

No, there's only one battery supply and it goes to the controller terminal 1 ("Battery").  The controller outputs ("Fan A" and "Fan B") pulse-width-modulated power to each of the fans to run and vary the speed of the fans.

Well, I'm only looking at the diagram, and it shows "Battery +" to both Fan 'A' and 'B'. 
 

I agree with Bob, battery positive to both fans. The controller will pulse negative to turn the fans on. Look at the high RPM mode, the (-) pulse is longer. In the low RPM mode the (-) pulse is short.

Last edited by wsinsle (8/16/2024 9:21 AM)

BobE wrote:

Well, I'm only looking at the diagram, and it shows "Battery +" to both Fan 'A' and 'B'. 
 

Whoops.  You're right.  I was looking at the little blobs to the right of the "BATTERY" text and thought they were minus signs (dashes).

BobE wrote:

John Ha wrote:

BobE wrote:

Well, I'm only looking at the diagram, and it shows "Battery +" to both Fan 'A' and 'B'. 
 

Whoops.  You're right.  I was looking at the little blobs to the right of the "BATTERY" text and thought they were minus signs (dashes).

As long as RTM gets the wiring correct, we're all good. 
 

 
That’s why I’m posting here.  To make sure I get it right.  lol

I’ll contact the auto cool guy and ask about the power source from the accessory position.   It sure would make life easier if I can use that green/red wire. 

I do have the brown wire to the blower motor that is not used.  Not sure if that runs in the accessory position or not.