2011 Monaco Diplomat dash instrumentation starts up or turns on without the key while parked.

[Nspiredadventurers]

I have a 2011 Monaco Diplomat 43DFT.  For the past year, the dash instrumentation will start up or turn on without the key in the ignition while parked at camp.  It is as if I put the key in and turned it in preparation to start the engine.  The dash and transmission display will remain on.  The center dash display will have "Engine Not Running".  When I do put the key in and try to start the engine, it will not do anything.  In order to start, I must turn off the chassis battery cutoff and remove the two gray relays next to the BIRD switch. Then I turn the chassis batteries on and start the engine.  I have replaced the ignition switch, replaced the BIRD, replaced the two small grey relays, replaced the Big Boy Solenoid, replaced all the small black relays in the electrical run box under the drivers seat area.  I have wiggled wiring and harnesses.  Nothing fixes this.  Occasionally, the engine, if running will not shut off when I remove the key.  I must go out to the electrical run box outside under the drivers seat and remove the ignition relay.  Two different service centers have not fixed this because the problem is intermittent and does not act up consistently.  It is driving me crazy.   Any advise.

[klcdenver]

Try Ghost Busters! Sorry just couldn’t resist. Good luck with this one. 

[Peterori]

Did you get a solution . I have the same exact problem withy 2011 Holiday DFT

[Guest Ray Davis]

My first thought is that some device may be back feeding the ignition, just a guess.   With the symptom in action have someone watch the dash while you remove fuses under the driver one at a time to see if one affects the problem.

Has any elect work been done recently?  

[Rikadoo]

When i worked for Ford we used to have the same issue, it was due to “fretting” between two connections. 
its prevalant whith vehicles that use control modules that use a buss system to comunicate with each other. Very intermintent, happens mostly in places with high humidity. The fix was to seperate connectors an smear “electrical grease” on the connectors.

[Tom Wallis]

My first thought was a malfunctioning BIRD. That can back feed the ignition. I had a similar problem once.  But then you said you replaced it. Anyway, it seems to me like the ignition wire that runs to the BIRD is worth some careful examination.

[Frank Bergamo]

Have you replaced or worked on alternator? I have had power backfeed to key switch. Solution was to install diode in ignition circuit. Hope this helps.

[Gary Cole]

The symptoms do not sound like back feed or a loose connection. The combinations of symptoms are too varied. I'm guessing that when you disconnect the power you are discharging capacitors with an invalid state in an electronic module which allows the module to act normally for a while. Same procedure in play when disconnecting the power to an electronic device, modem, router,computer, etc for 1 min or so gives capacitors time to discharge and magically fixes the device. What module proves the necessary on conditions before allowing the start process? I don't think its the ECM because i read somewhere that the starter in a Cummins will engage with a defective ECM. No expert on this.
 

Edited December 22, 2021 by Gary Cole

[Steven P]

Any chance it could be related to a rear engine bay start switch?  I don't have one but when i was reading your post I was thinking ignition switch til you said you replaced it.  Then I remembered some have a rear engine switch too.  Other than that, I got nothing.