4104 start / run switch issue

[Nel]

Hey Guys,
I have a 4104 / 671 , here's what it's doing and I think the PO wired it this way as a theft deterrent. If I turn on the run switch , it will disable the start switch. so to start the bus when its cold , I just leave the run switch off and hit the start switch and it starts fine , once it's running I turn on the run switch. the solenoid does click when I hit the switch so I know it works .

Now once the air pressure is up and I want to start the bus, I have to leave the run switch off, hit the start switch and after the engine is cranking , I have to hit the run switch and it starts . you have to do this switch toggle quickly because as soon as you hit the run switch it disables the starter.
   to me it's a PITA , so where should I look for this wiring mod. by the switch in the dash or by the solenoid valve in the engine compartment?   Thanks

[bevans6]

You are saying the engine runs fine with the switch in the run position, but the starter won't crank over when the run switch is in the run position.  If your bus has a rear switch box holding the rear start switch and the run/off switch, that is where I would look.  The run switch shouldn't have anything to do with the start switches, I would think.

Brian

[Nel]

I'll check that, Thanks

[gus]

The engine fuel shutoff is momentarily air operated so the engine will start anytime it is cranked regardless of the run switch position. It only stays in the off position a few seconds so it is always in the run position.

The problem with this is it can't be shut off with the run switch until air pressure has built up. Very inconvenient in a runaway engine or any other situation which calls for an immediate shutdown!!

It can be shut off (maybe) with the kill switch if it is working - many aren't.

Run On actually only turns on the electrics, has nothing to do with the engine.

The run switch in the rear may be off, it is too easy to accidentally hit those switches. I can't remember the exact wiring, you need to check the wiring diagrams.

[Nel]

I will check that out , Thanks