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I was at a local salvage yard to pick up a part for my wife's car and on a whim I asked if they had the fans for a Chevrolet Volt. Sure enough, they had one.
For $75 I got dual 300 watt 12" brushless SPAL fans in a 26.5 x 16.5" shroud. These use the same connectors as the C7 fan. I am going to do some testing with them with the Holley Dominator.
Andrew
What's the depth of that shroud assembly? Sounds great!
Any 20.5 wide x 20.0 ish shroud/fan combos out there? Bonus if the fan is not centered. I need at least 2 inches clearance at the top. I might be asking for too much.
If you have the fan/shroud in the pic, you only need a PWM controller to run them.
TO ME, the best are either the new Northern Radiator unit designed and developed by Carl Casanova of Vaporworx and Brian Baskin of Delta Circuit Controls (DCC), or DCC's own units. Both VERY compact and super easy to wire. Plus they can handle a lot of amps. Google either/both to get details.
Stay away from Derale units. Even though their internals run under DCC patent, Derale cut corners making them and they have a poor record for dependability.
What year is that from? I see the Volt has 2 generations of fans. The 1st doesn't appear to be brushless but I could be wrong. That's an excellent price for the set. Any suggestions on an online used parts supplier with reasonable prices? Volts are hard to come by in southern Idaho. lol
Great thread with a ton of information. I'm shopping now for a fan for my Camaro as I'm also having some cooling issues. Does anyone know the diameter of the fans for the C7 or SS Camaro? I'm hoping to keep my existing shroud and just make a mount to hold the fan. Similar to the retro-fit fans that Vintage Air offers.
Great thread with a ton of information. I'm shopping now for a fan for my Camaro as I'm also having some cooling issues. Does anyone know the diameter of the fans for the C7 or SS Camaro? I'm hoping to keep my existing shroud and just make a mount to hold the fan. Similar to the retro-fit fans that Vintage Air offers.
Quite often you can find an OEM electric fan/shroud cheaply. Or if you want new parts, still look in the "previously owned emporiums" for what may fit (bring a tape measure), see what may fit, then get a new Dorman unit. Even they can be pretty reasonable. Then hook it up with a PWM controller and you ARE in business!
have you ever tried using bts7960? can this replace ecm?
I googled this. It APPEARS to be able to replace any of the proprietary OEM modules. Does anyone know anything about these? It still needs a PWM signal to vary speed...
It would appear that Chrysler/Jeep modeled theirs after something like this...
I googled this. It APPEARS to be able to replace any of the proprietary OEM modules. Does anyone know anything about these? It still needs a PWM signal to vary speed...
It would appear that Chrysler/Jeep modeled theirs after something like this...
This would sorta work. However, it would be very noisy. Because most PWM sources, like Holley for example, have a limited maximum frequency. Remember that a typical Holley PWM frequency is 128hz and to get a fan to be quiet you need to be at around 20,000hz. The fan modules described above are quiet and run at very high frequencies.
At higher frequencies, the maximum current rating is probably derated. And I would guess that 43A is maximum rating, probably not a constant rating.
In any case, you could add an arduino nano processor to one of these and have it convert the 128hz to some higher frequency around 20,000hz and it should work for moderate amperage fans around 20A is my guess.
These things are a full H bridge which means it's bidirectional. Doesn't make a real difference, but extra circuits to make more heat.
Hey Carl, I am in need of some help setting up code on my Arduino nano for a brushless BMW fan. I have been trying to compile and upload the previous code for it that you posted and can't figure out what the errors mean. (First time with Arduino). I know how to disassemble, but this is over my head. I've uploaded the error message if you have time to take a glance. Thanks man
Last edited by Stokes1114; Jul 17, 2021 at 06:05 PM.
So it sounds like instead of going to an ECM, your temp sensor goes to an MSD box. Most likely, the MSD box has a series resistor going to 5V just like the ECM would and the other sensor wire is likely going to ground. The way to find the value of the MSDs series resistor is to measure the voltage at any of the temperatures that are in your chart.
Lets do an example. Let's say you measure your voltage at the sensor while it's connected to the MSD box and it is 120 degrees. According to your table the sensors resistance is 1338 ohms at 120 degrees.
If you measured 2 volts then Rmsdbox = E / I = (5 - 2) / ( 2 / 1338) = 2007 ohms
If you measured 1.5 volts then Rmsdbox = E / I = (5 - 1.5) / ( 1.5 / 1338) = 3122 ohms
Make some voltage measurements and let's see what the resistance in the MSD is. Once we know what the MSD series resistance is, we can figure out the voltages at 180 degrees and 198 degrees and pop that into the code for starting up the fan and full power.
hey sir, should be getting around to getting voltages in-line with the MSD box here soon. Project has been on the back burner for a little while. I’ll post here what the readings are. Thanks again
Those who want to PWM control fans independent of PCM or existing temp sensors and have soft start, roll up your sleeves for this DIY. Uses a separate temperature sensor controlling a C6/Ford PWM fan control module and A/C activation. You gotta build it and test it yourself. I built one and bench tested it.
Features a fan start temperature (180F in this example) , a fan full power temp (200F in example) and variable fans speed in between these two. C6/Ford PWM fan control operates at 20,000hz. so fans run quietly and have soft start.
If A/C clutch is on (or any 12 volt signal on clutch input), fans run about 1/2 speed (adjustable of course) and increase if temp increases. Temp sensor is a stainless steel tube about 3/16 inch. I would attach this somewhere on the hot side, either on the radiator hose or in the radiator fins, out of the airflow.
Here is the code. Change the stuff in the user adjustable section to your liking.
If you want the code in a copy-able format, PM me.
Oh, I forgot to mention that the temperature and PWM duty are continuously output to the USB port to help in adjusting anything or monitoring the operation.
I forgot about this thread. On my 2005 Rainier, the E40 VCM (flashed with HP Tuners and using Corvette fan settings) operates the Mercedes PWM fan that replaced the mechanical one perfectly based on coolant temp, but it won't do anything based upon AC pressure. I sent the problem up the chain at HP Tuners and they can't find anything wrong.
I've been learning about Arduino to try and make a standalone using the Nano.
EDIT: Deleted out of date schematic and files. I have updated schematic & files in a follow-up post below.
I'll attach the code I have written as a PDF and also my schematic (updated with PWM output frequency mod). I bought the simulator program, but keep getting errors such as "Unknown command" when it reads other same-name commands OK. I think it is a simulator issue and am getting ready to field test the Nano. In summary, I'm using a voltage divider setup to read the OEM coolant temp sensor (I found a datasheet for it and made some calcs), and also reading the OEM AC pressure sensor since it is a 0-5V sensor. These each have an analog pin input, and output PWM to a digital pin. I am learning about using the IF statement to establish which sensor has priority as well as several fan speeds based upon either temp or pressure. It's a lot to learn. There is no monitor out setting here, as I plan to monitor the readings in HP Tuners scanner software (which is where I got a lot of the pressure sensor data).
Last edited by V8 Supra Builder; Jul 18, 2021 at 02:18 PM.
Reason: Deleted incorrect schematic
I tested it with a PWM generator.
It worked fine with a PWM frequency between 100 and 312 hz. Anything out of that range, it shut down. I would guess 128hz that is being used by other fans would be good.
Full power was at 7-10% duty and low speed was 90%. anywhere outside that range it shuts off, so 0% or 100% duty are off.
Looks like it came in these:
That looks like the one I'm using in my Durango swap and it's probably similar to the one in my Rainier project. I have a question about the frequency since you did some testing. I have not tested the Mercedes fan in my Rainier, but as noted am working on adapting a Nano Arduino to operate it. I'm concerned since the Nano outputs PWM at 490 Hz, it may not operate this fan. Any thoughts on this?
EDIT
Solved- this page shows the codes available to modify the PWM frequency on the Nano. It's a one-line code added to the setup area of your sketch (file). One of the available frequencies is 122.55 Hz, which is good for these fans. He has other pages for the Uno and Mega.
Last edited by V8 Supra Builder; Jul 17, 2021 at 06:48 PM.
