PWM cooling fan(s) control using ECM

[Old66Tiger]

Originally Posted by Z06vette

After reading thru this entire 35 pages, I have a question on the fan controller. Right now im running an LS2 w e38. The e38 was from an 08 2500 6.0 truck w clutch fan. I am NOT looking to run the fans in PWM, as my harness is wired to run them on/off. I have a guy that tunes for me w efi live. We eventually got the ecm to work the fans, but they pulse the when running. He can command both fans and they run full speed with no pulse. I believe I am missing the "discrete" setting..., and it is still in PWM mode. This is my first e38 after many 411's in numerous swaps. Also, I am running a trinary switch for the AC. Is there any ecm settings that need to be altered to make all this work together?
Great thread, and thanks for the help.
Scott

Scott. It is possible that you are setup in discrete but the VA system is pulsing the fans through the controller via the trinary switch. I was told by VA that the evaporator controller will turn the AC compressor on and off based on what the probe is seeing in the coils under the dash.

I am in the process of gathering all of the parts to set up my fans to run PWM with the use of a AC pressure switch. It will go in line with the trinary and should allow the fans to work on pressure rather than the state of the compressor clutch. I will be posting all of these parts once I get everything figured out.