Needing some insight. 2010 Kenworth T8 1XKDD49X8AJ262684 with Cummins ISX 79360158 with an engine fan that's constantly running when parameters are set like they should be.
AC input switch and coolant temp sensor are reading correctly. Fan control status states that engine fan is on due to fan control switch or data link control. Fan switch is off and even with fan override switch disabled...still reads the same. If the parameters for on/off voltage is flipped the fan stays off constantly and fan override switch does not engage fan.
Fan switches have been swapped. Test ecm was tried. Fan override was also disabled with the test ecm and still read the same fan status. Manually powering the fan solenoid with a probe works as it should kicking on and off.