PWM cooling fan(s) control using ECM

[SlowProgress]

Originally Posted by andrewb70

Scott,

Do you know the exact specifications as to what the controller is looking for?

Andrew

I haven't gotten that far yet. I figured when I get there I would try to get in touch with Spal, or bug someone smart like Mikels. I don't even have the ECU installed yet.

Scott

[andrewb70]

Originally Posted by SlowProgress

I haven't gotten that far yet. I figured when I get there I would try to get in touch with Spal, or bug someone smart like Mikels. I don't even have the ECU installed yet.

Scott

Scott,

Please post whatever information you can find. The CTSV fan seems like a good value give the output and the fact that the PWM controller is built into the assembly.

Do you happen to have rough dimensions? Also, if you have more picture of how the fan is mounted to the radiator, that would be appreciated.

Andrew

[SlowProgress]

Andrew it is roughly 22x24 inches. I will post up some tape measure photos. C&R did the drawings and it picks up six holes already on the fan. I cut off some of the tabs that were not needed. I thought it was a good value as well. You do need to modify the core support which I was planning anyway to use this big fan.

[SlowProgress]

Originally Posted by andrewb70

Scott,

Please post whatever information you can find. The CTSV fan seems like a good value give the output and the fact that the PWM controller is built into the assembly.

Do you happen to have rough dimensions? Also, if you have more picture of how the fan is mounted to the radiator, that would be appreciated.

Andrew

Andrew the fan just mounts with six screw (three each top and bottom). The radiator is actually sort of designed around the fan. There is also a bracket in front to mount the Vintage Air condenser.



The overall fan and radiator height is around 22 inches.



The width of the fan is around 24 inches and the radiator tank outside to outside is about 28.5 inches.



You know the guys at C&R are really helpful. If you asked for the drawing in .PDF I think they would share it with you.

[4wheels]

Just to clarify, all of the DC brushless fans that I am familiar with have the BLDC controller built into the fan and then take a speed control signal as an input.

Other vehicles that have DC brushless variable speed fans are:

• 2014-2016 CK trucks including Silverado, Sierra (dual Bosch fans)
• 2015-2015 CK SUVs (Escalade, Tahoe, Yukon, Suburban) - also dual Bosch fans
• 2016 ATS-V
• 2016 CTS-V
• 2014-2016 C7 Corvette
• 2015-2016 C7 Z06 Corvette
• 2016 Camaro
• and many other newer vehicles.

They can usually be identified by the connector configuration and wiring. Should be three wires - two large gauge wires (power and ground) and then a third small gauge wire that is the speed control signal input to the fan.

Originally Posted by andrewb70

Scott,

Please post whatever information you can find. The CTSV fan seems like a good value give the output and the fact that the PWM controller is built into the assembly.

Do you happen to have rough dimensions? Also, if you have more picture of how the fan is mounted to the radiator, that would be appreciated.

Andrew

[mikentosh]

Wondering if anybody has troubleshooting advice for the PWM signal coming from an E38 ECU? I'm not seeing any PWM signal coming out from X1 pin 58.

I took my multimeter and put black probe to DkGrn wire coming from X1 pin 58, and red probe to battery positive terminal, and set to DC volts. Turning key on I can see the voltage go up to about 1.2V but regardless of toggling fans and duty cycle in HP Tuners I don't see any change. I would expect to see either ~5V or ~12V across here but do not. I didn't even bother to switch my multimeter over to duty cycle measurement, but assumed without the higher voltage its not working.

Any ideas on further troubleshooting? Pin 58 is a ground PWM signal correct?

[andrewb70]

Originally Posted by mikentosh

....

...Pin 58 is a ground PWM signal correct?

That part I know to be correct, but I can't help with anything else.

Andrew

[mikentosh]

Originally Posted by andrewb70

That part I know to be correct, but I can't help with anything else.

Andrew

Thanks. I looked at it again on the weekend and realized that I was monitoring it while it was hooked up to the C6 fan relay. Once I disconnected the fan module I see it taking 12V to ground when key is on, regardless of fan state in the ECU. Interestingly I also flashed the ECU back to discrete fans and am observing the same situation, so I'm going to give up for now and wait until I've switched over to the Holley Dominator setup.

[andrewb70]

Originally Posted by mikentosh

...so I'm going to give up for now and wait until I've switched over to the Holley Dominator setup.

Now that, I can help you with!

Andrew

[dhanks]

For what it's worth, I'm using Dakota Digital's VHX + fan controller with my GM LSX and it works great.