PWM radiator fan control
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PWM radiator fan control
I am trying to get my new ms3pro (firmware 1.4.1) to control my radiator fan on my 1990 mustang (and the running of the engine too). I know that Tuner studio can control the fan with a simple on and off configuration, but I was trying to get the ms3 to PWM the fan control based on coolant temp. When the car is off, fan off. When car is running turn on the fan and control the fan speed based on the coolant temp. So if the engine is cold the fan is off, as the coolant temp starts to increase, the fan will start at a slow speed and as the temp continues to rise, have the fan speed try to maintain that temp until it gets to full speed. Ideally I want to try to target about 200 degrees with varying the fan speed. I am thinking this can use some sort of feedback loop to vary the fan speed. I am using a ford mark 6 fan, it has a very large inrush current when it cycles on and off, so if I can PWM the fan it should limit this inrush current. The "Fan control" feature of tuner studio only allows for on and off of the fan control not PWM control. The generic PWM outputs under "Advanced engine" only allow for one axis to be load (for me coolant) and the other is not changeable and is only referenced to RPM. Ideally I want one axis to be coolant temp the other to be Load output which is directly related to fan speed. So at low coolant temp, low load (slow fan) and at high coolant temp high load (fast fan). I hope this makes sense, this would be a great feature to add to the MS3 Pro. I know there are specific PWM fan controllers on the market but I strongly think that MS3pro can do this with the correct programming, the only thing you would have to buy is a solid state relay to handle the large current of the fan. I have found that a 2000's Dodge Caravan has a solid state relay in it for this function and is cheap at a salvage yard!! Any help would be greatly appreciated. Thanks, Scott
Re: PWM radiator fan control
Someone on another forum recently looked into this. They called a fan manufacturer and found out that fans should be PWM'd at a much higher frequency than the MS3 supports. In the kHz range instead of just 200Hz.
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Re: PWM radiator fan control
http://jbperf.com/pwm_converter/index.html
This will allow higher frequencies. I plan to use this and a solid state relay to control a Taurus fan with closed loop control.
This will allow higher frequencies. I plan to use this and a solid state relay to control a Taurus fan with closed loop control.
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Re: PWM radiator fan control
Mercedes and GM (Corvette C6) fan controllers by Siemens
photo here http://www.frankencis.com/Forum/aft/32
Mercedes units have ignition and PWM signal lines
Corvette just has the PWM
Both have very high current ratings and include soft start of the fan by default
~100hz signal ground switched between 10% and 90% duty on the PWM line is all that is needed for the Corvette unit
The Mercedes required 12v to the ignition terminal, and ~100hz signal ground switched between 10% and 90% duty on the PWM line
10% is off on both
90% is full speed on both
values between 15% and 90% produce a variable speed relative to the signal
if no PWM signal found on the Mercedes unit and ignition is on it will go into a full speed failsafe mode
The Mercedes unit could be run with just the ignition signal as a basic soft start fan controller
photo here http://www.frankencis.com/Forum/aft/32
Mercedes units have ignition and PWM signal lines
Corvette just has the PWM
Both have very high current ratings and include soft start of the fan by default
~100hz signal ground switched between 10% and 90% duty on the PWM line is all that is needed for the Corvette unit
The Mercedes required 12v to the ignition terminal, and ~100hz signal ground switched between 10% and 90% duty on the PWM line
10% is off on both
90% is full speed on both
values between 15% and 90% produce a variable speed relative to the signal
if no PWM signal found on the Mercedes unit and ignition is on it will go into a full speed failsafe mode
The Mercedes unit could be run with just the ignition signal as a basic soft start fan controller
Steve
Re: PWM radiator fan control
Generic PWM table could be used to drive a PWM coolant fan with one axis being clt obviously and the other being VSS. That's how I'd do it.
Sydney, Australia
1971 Holden Monaro HQ
MS3X Sequentially fuelled 400 Pontiac
1971 Holden Monaro HQ
MS3X Sequentially fuelled 400 Pontiac
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Re: PWM radiator fan control
Very cool idea.stevevp wrote:Mercedes and GM (Corvette C6) fan controllers by Siemens
photo here http://www.frankencis.com/Forum/aft/32
Mercedes units have ignition and PWM signal lines
Corvette just has the PWM
Both have very high current ratings and include soft start of the fan by default
~100hz signal ground switched between 10% and 90% duty on the PWM line is all that is needed for the Corvette unit
The Mercedes required 12v to the ignition terminal, and ~100hz signal ground switched between 10% and 90% duty on the PWM line
10% is off on both
90% is full speed on both
values between 15% and 90% produce a variable speed relative to the signal
if no PWM signal found on the Mercedes unit and ignition is on it will go into a full speed failsafe mode
The Mercedes unit could be run with just the ignition signal as a basic soft start fan controller
James, can we drive that thing? Electric water pumps, fuel pumps, cooling fans, traction control devices, electric power steering.... Who knows???
Andy
Re: PWM radiator fan control
I pulled a fan shroud/controller off a Lincoln Zephyr at the junkyard and it had this module on it.
Given that I want to be able to utilize MS's fan control features, I don't think I want to use a generic PWM output for this. I'm currently using INJ1 as a ground switch to my fan relay. What would happen if I instead connected that to the module's PWM input and grounded the PWM input. I'm assuming it'd see 100% duty cycle and the fan would run at full speed - is this a good assumption?
Given that I want to be able to utilize MS's fan control features, I don't think I want to use a generic PWM output for this. I'm currently using INJ1 as a ground switch to my fan relay. What would happen if I instead connected that to the module's PWM input and grounded the PWM input. I'm assuming it'd see 100% duty cycle and the fan would run at full speed - is this a good assumption?