Need help guys this one has been running me around for over a week. A 2003 model miller 250 NT with Onan 20.5 hp engine. Engine will crank but no start. (1) new fuel pump OK. No current to anything except grey wire (oil pressure switch) in run idle. Here is what I have done so far. NO "snap or click" when switch is turned on.
Fuel shut off works with external 12v. No voltage otherwise.
Stop diode measure of continuity OK to values
Fuse in Harness OK Diode checked with digital meter .779 / analog @1k .4 @10k .8 values in one direction only (seems to be OK)
Stop relay test OK
Here is where I get in real trouble. 12v at engine to welder plug (red) 12v at switch.
Switch on run idle 12v to grey (oil pressure switch) Run 12v to grey.
Switch start 12v to yellow (start)
Switch to run Idle 12v to grey oil switch wire and to H term on PC module (pull to Idle) NO current out of Module not even to hour meter.
Switch to RUN Grey only (oil pressure switch)
I am left scratching my head, to beleive that I have a module problem, should I not have another 12v leaving the module to the blue wire (reason for diode in yellow line to prevent startup) blue wire +red +white at pressure switch has nothing. Or am I not interpting the oil pressure switch correctly. Is there a test for the module somewhere please send a link for guided step by step test. PLEASE HELP Thanks