Adding a manual fan switch??

[snailexpress]

(02-15-2017 )JMBT Wrote:  snailexpress, So you had no fault codes from the Cummins side when you did this on your truck with a cummins motor? That does makes sense, all is under VECU control. I really appreciate the info! I will check to see if my green connector has PA19 pin.

Should be no faults from cummins.
Here is how it works. Coolant sensor signal from Cummins ECU going to VECU and VECU commands fan to ON. so you can turn fan On even the coolant temp is below triggering point.