PWM Electric Cooling Fan

[NIGHTMARE]

Does anyone have an active table for PWM+ on a electric cooling fan? I want to try going PWM on my fan, but was wanting to look at someones table to see how it should be setup. Thanks in advance.

[Danny Cabral]

I want to try going PWM on my fan, but was wanting to look at someones table to see how it should be setup.

I don't have an example PWM Setup Table, but there's some information in this LINK (in framed box) to get you started.

[S2H]

I did something similar to this on a customer's car. Most PWM fans are looking for a frequency of 128.

[Danny Cabral]

S2H showed you exactly what you asked for; an example PWM Setup Table.
Of course, you'll first create & configure the custom Output(s) in the I/O ICF.
Name it, select PWM+ or PWM−, Enable & Configure it with Sensor Input Triggers (if necessary).

[NIGHTMARE]

Thank you Gentlemen. This is exactly what I was looking for. I already have the I/O setup, just need to switch it to PWM+ instead of +12V, which I'm currently using. I'll be ordering an 80 amp solid relay to accomplish this.

[andrewb70]

I did something similar to this on a customer's car. Most PWM fans are looking for a frequency of 128.

Scott, are you by chance using the C6 Corvette fan controller?
http://www.amazon.com/ACDelco-15-808.../dp/B000EQP2AS Andrew

[BITE_ME]

Thank you Gentlemen. This is exactly what I was looking for. I already have the I/O setup, just need to switch it to PWM+ instead of +12V, which I'm currently using. I'll be ordering an 80 amp solid relay to accomplish this.

Don't forget to heat sink it. Even the 100 amp unit can only deal with 25 amps with no heat sink.

[andrewb70]

Well, I got this working tonight. Works awesome!!!

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

[silverbullet9]

Nice job, Andrew! I noticed you stated not to set the fan duty cycle over 90%, as the fan will not work. Is this specific to the Corvette fan controller, or does it have do with the Holley PWM settings? Mike

[andrewb70]

Nice job, Andrew! I noticed you stated not to set the fan duty cycle over 90%, as the fan will not work. Is this specific to the Corvette fan controller, or does it have do with the Holley PWM settings?

Mike, I believe it has to do with the C6 fan controller. As I understand it, the 128 Hz value is for 90% duty cycle (all this is above my pay grade, so I could be saying something really stupid here). When the fan is running at 90% duty cycle, it's blowing really...I mean really hard. Andrew

[Dave_62]

If I remember correctly, on most GM PWM controls, values of greater than 90% and less than 5% is for diagnostic use.

[andrewb70]

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.




Then I fired it up and watched the temp. 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 am really pleased with how the coolant system and the fan controller worked out on this build.

Just a quick update: I was able to set the fan speed to 25% at 190°-200°, and it maintains coolant temps at the desired 192°-195° range. I also configured my PWM Table to reflect MPH vs. fan speed, cycling down the fan at speeds over 40 MPH. Andrew

[andrewb70]

So, I'm not ashamed to admit that I might be slightly obsessed with the ability to control my fan speed. Recently, I had to add coolant to my system (I was running straight water in the summer) so that I don't hurt anything during the long WI winter. After adding the coolant (good to about -40°) I noticed that the engine ran about 4°-5° hotter under previously noted conditions. This of course caused the fan to run faster per the table that I programmed. So I decided to "retune" the table and just set it to work the best it can in my car. For me, "the best it can" is running the fan as slowly as possible, while maintaining a target temperature. But what is that target temperature? LOL!

I know I have a stock thermostat, which by all accounts is 187°. Given that information I can turn off the fan and just watch what the temperature does under varying conditions (granted all of this is dependent on ambient temperature, and ideally, I'd incorporate it into the fan control strategy for optimal results, but even GM doesn't do this. Didn't I say that I might be slightly obsessed?) Driving normally around town (like grandma, top speed 35) the temperature never got above 191°-192° (about 50° ambient). I then took it on the highway and cruising at a steady 75 MPH the temp was stable between 194°-195° (all this with the fan off).

So I configured my table as follows at vehicle speed below 40 MPH.
Temp °F= Fan %
194°=5% (Off)
200°=10%
210°=20%
Then it ramps in rather quickly (I don't recall the exact numbers). The fan basically never kicks on around town and temps is steady at 191°-192°.

For vehicle speed above 40 MPH I just configured the cells to be one value off, like this:
194°=5%
200°=5%
210°=10%
ETC. Again, ramping in quickly. Temp is steady at 194°-195° without the fan. I don't know if this is optimal in terms of thermal efficiency. Probably not because my engine seems to run cooler than it would in the donor vehicle (2009 Colorado pick-up). But in terms of my target goal (cycling the fan as little as possible) I think I succeeded. Anyway, I thought I would share for anyone that cares. Comments, questions & opinions welcome.

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

[TurboChapman]

Thanks for the great read Andrew. Looks like a very efficient way to run the fan. I wish I had seen this before purchasing the Entropy radiator & dual fan setup. I believe I can use your method of control for both fans, as long as you can run fans PWM through relays. Thanks again.

[andrewb70]

Glad to help! Andrew