I have an Onan Marquis Gold 5500 generator. The problem I have is that after it starts it will shut back off, but if I pull on the #1 Ign. wire I can get it to run continuously. I have to pull on it pretty firm putting the tension on the plug going into the control board. As soon as I release the wire the generator shuts down. Initially when I was having problems with it running I was getting a very weak spark to that cylinder and I thought that it was the magneto. I replaced it and ran great for about an hour. It then shut down and I found by accident the problem with the wire. I have replaced the wire and the control board but still have the problem. The plug appears to be making contact but I cannot confirm this since the control board is sealed. Any ideas or recommendations would sure be appreciated.
Weird generator problem
- Thread starter Magmach
- Start date
G
Guest
Guest
Magmach,, are u saying u are pulling just the #1 plug wire ??? and it runs ,, but u also mentioned u replced the board and mag ,, i am kinda confused on what wire u say ,, the mag wires are like spark plug wires ,, they can be replaced seperatly ,, and as Len has said ,, u might be losing a ground ,, but with my training from cummins/onan ,, sounds like u might have a ac voltage sensor problem ,, but i am still not ruling out the ground thingy ,,, it can happen ,, but need a little more info on what it is really doing ,, and if u pm the model number and serial number i can ck the schematic on the wiring 
The wire that I am pulling is the #1 control wire that runs from the board to the magneto. That is the wire that I replaced to rule out a dead short. I am pulling on the end that goes to the board. I just found out how to read the fault codes and have not checked them yet. Maybe they will shed some light as to what the problem is.