Wiring an Electric Cooling Fan - Holley EFI

[carbuff]

I certainly don't have any inside knowledge about either the Holley or the Corvette module, but I do know how PWM works in general. :) I really believe that if you are turning the voltage to the fan on & off at such a high rate that you will burn eventually out the motor, and thus the need for the module to generate a scaled voltage. I wish I had one of the Module here to test myself to confirm it.

I was seriously considering changing my currently 2-relay setup for my dual fans to use the Corvette module. However, I ran into a roadblock on how to setup the HP EFI for the fans to be on when my A/C is running. It's not clear to me in the PWM Configuration panels how to take an on/off input like my A/C IAC Kick signal and feed that into the PWM Duty Cycle table. I can enable the output with the Kick signal, but that's not right because it would disable the fans if the A/C isn't enabled.

I believe I need an input that is a scaled version of the A/C lines pressure, which is how I think the Corvette ECU handles things, but that's a whole other investigation into how to add a sensor for that and then get the Holley to read/scale it correctly. I may experiment with this later on, but for now I'm going to live with my loud fans.

[andrewb70]

Hey Bryan, I just made all this work with the Dominator. I don't know enough about the HP, but it works like a charm:

FYI: If anyone is looking for information regarding the connector for the C6 fan controller, here it is:
http://www.pro-touring.com/threads/1...dule-Connector. Andrew

[Danny Cabral]

Hey Bryan, I just made all this work with the Dominator.

Andrew, thanks for the great video on this. It's very helpful.
http://forums.holley.com/showthread....ic-Cooling-Fan (Additional Information)

I don't know enough about the HP, but it works like a charm:

Yes, this works the same with the HP ECU as well.
http://documents.holley.com/techlibr...useanddiff.pdf (Holley HP & Dominator ECU Differences)
http://documents.holley.com/199r10516.pdf (Holley 558-400 I/O Auxiliary Harness Instructions)

[andrewb70]

Andrew, thanks for the great video on this. It's very helpful.

Danny, feel free to pass that video around. Andrew

[71_bowtie]

I purchased the Holley 534-134 cooling fan relay kit. I wired it per the instructions. I wired the green/white wire up to I/O Auxiliary Harness 558-400 gray/yellow wire. When l turn the key on, it's blowing the inline fuse on the relay kit. Any help would be much appreciated.

[Danny Cabral]

I purchased the Holley 534-134 cooling fan relay kit. I wired it per the instructions.

You can't exactly follow those instructions (Link); they're from the Commander 950 EFI system.

I wired the green/white wire up to I/O Auxiliary Harness 558-400 gray/yellow wire.

The Holley 534-134 Cooling Fan Relay Kit is wired for a Ground signal to energize the relay's coil terminal #85. The Holley 558-400 I/O Auxiliary Harness B12 gray/yellow (Output #1) wire is a +12V Output. So you'll need to permanently ground relay terminal #85, and cut the jumper wire from terminal #86 (to #87), and connect it to the gray/yellow Output #1 wire. Leave the fused +12V battery power wire connected to relay terminal #87.

If you'd like to wire the Cooling Fan Relay Kit as is, just use the B3 gray/green Output #4 or B10 gray/black Output#3 Ground signal.

When l turn the key on, it's blowing the inline fuse on the relay kit.

You have something wired wrong (short circuit), or your fan draws more amperage than the fuse is rated for.

[71_bowtie]

Thanks Danny! I got it to work. My fan has an amp draw of 11 amps. When the fan turns on, it's popping the 15 amp fuse, but not a 30 amp fuse. Obviously, electrical isn't my forte. Will there be any issue with running the 30 amp fuse?

[Danny Cabral]

Will there be any issue with running the 30 amp fuse?

No, that will be fine.

[andrewb70]

Thanks Danny! I got it to work. My fan has an amp draw of 11 amps. When the fan turns on, it's popping the 15 amp fuse, but not a 30 amp fuse. Obviously, electrical isn't my forte. Will there be any issue with running the 30 amp fuse?

When the fan kicks on, there's a spike in current, in your case, more than 15 amps. That's another advantage of running fans with PWM, there's no current spike at startup. Andrew

[FuelieNova]

This thread should be a sticky. A lot of guys are confused on how to use PWM for fan control, and Andrew did an excellent job with the video. Tom

[StreetPro]

I wired up my two electric fans like Danny discussed in the first part of the topic. I liked the idea of having the fans off, with the engine not running and ignition on. No problems there, they work fine. But I thought that I could use the A/C Kick input to turn on the fans with the A/C on. But I found out that when using the switch input, it's going to override the sensor input. In other words, if you enable A/C Kick switch input, the fans will not come on with the sensor input, or if I disable the A/C Kick, the fans will come on with sensor input and will turn off when you turn the A/C on (A/C Kick input active).

I know I can hard wire in the A/C to the fan relays, but that will bypass having the fans off at key-on engine not running if the A/C is on. I know you can turn the A/C off.

I just didn't know if I'm missing something here? Other then install a pressure switch in the A/C. I'm not going to do that on it, I know if that's the case I'll just hard wire it.

[andrewb70]

This thread should be a sticky. A lot of guys are confused on how to use PWM for fan control, and Andrew did an excellent job with the video.

Thanks Tom. Just to close the loop on this, earlier today I finished up the bracket for the C6 fan to mount to my radiator. Once it was installed for good, I figured it was time to put this thing to the test. I filled up the radiator and started the engine, and just let it idle. I got it up to about 220°, and the lower radiator hose was nice and hot, which means the thermostat opened up. I let it cool down and I just checked the radiator, and it looked to be about half full, which means the thermostat did open and the block filled with water. I topped it off, put the cap back on, and tweaked the PWM vs. CTS table to resemble this one from a 2013 Corvette (scaled it down about 7° because I thought my thermostat was 180° instead of 187° like the Corvette).



Then I fired it up and watched the temperature. It stabilized at 193°/194° just sitting there idling in the garage. At that temperature the fan is only at 40%, which means it can sit there forever. I'm really pleased with how the coolant system and the fan controller worked out on this build.

FYI: If anyone is looking for information regarding the connector for the C6 fan controller, here it is:
http://www.pro-touring.com/threads/1...dule-Connector. Andrew

[fast82lx]

Andrewb70, I have been following your fan controller install both on here and on YB. One question for you, when the fan comes on at "10% at 190°" does the engine bog down any for a split second then recover? The fan could cycle on & off a billion times at "10%" and the idle speed would not change? You understand what I'm getting at? LOL!

When the electric fan comes on, on my 2014 Mustang the idle never changes, you don't know the fan ever comes on unless you listen for it. That's how I would like my fan to operate with the Holley. Does your method work like this?

Danny, your method of using a relay with no PWM; does your idle bog or change when your fan comes on? You using the A/C Kick?

[Danny Cabral]

@ Andrewb70, I have been following your fan controller install both on here and on YB. One question for you, when the fan comes on at "10% at 190°" does the engine bog down any for a split second then recover?

I'm not Andrew, but I'm sure 10% electric fan operation doesn't interrupt his engine's idle.

When the electric fan comes on, on my 2014 Mustang the idle never changes, you don't know the fan ever comes on unless you listen for it. That's how I would like my fan to operate with the Holley. Does your method work like this?

This is exactly what happens with my engine/electric fans. Electric fan(s) that bog the engine down, are usually caused by a ground problem.

Danny, your method of using a relay with no PWM; does your idle bog or change when your fan comes on?

Absolutely not. Most of the time, I don't even know it came on. My Holley Digital Dash has an Electric Fans indicator light.

You using the A/C Kick?

No, I don't need the IAC Kick feature.

[andrewb70]

Andrewb70, I have been following your fan controller install both on here and on YB. One question for you, when the fan comes on at "10% at 190°" does the engine bog down any for a split second then recover? The fan could cycle on & off a billion times at "10%" and the idle speed would not change? You understand what I'm getting at? LOL!

When the electric fan comes on, on my 2014 Mustang the idle never changes, you don't know the fan ever comes on unless you listen for it. That's how I would like my fan to operate with the Holley. Does your method work like this?

It works exactly like that. When the fan starts to spin, there is no noise at all. The idle doesn't change, nothing changes. Even when the fan spins up to 70% (this rarely happens), you just hear wind noise. The fans speeds up & slows down gently, and it's virtually silent. I have my Holley Digital Dash configured to show the fan speed as % duty cycle, so I have a good handle on how fast it's spinning when I drive. Andrew