RV Repair: Motor will not shut off., simplest thing, toggle switch

Question
Just purchased a 1999 Fleetwood Discovery 36T. When I turn the key off and remove it from the ignition swith, the assesories will shut off but not the engine. By removing a 12v 30a relay in the engine compartment, it will shut off. Tried a new relay but still had the same problem. By tapping on the old relay, the engine will momentarily quit firing, but not shut off. Not much to go on. Hope that you can help.  Thanks, Henry

Answer
Hi Henry:
These kind of problems can be difficult. Somehow your ignition circuit is staying energized with key off. The coach is old enough for someone to have done some creative wiring. Look for a toggle switch near the dash that stays on. Change the ignition switch, may have an internal short. It that does not fix it probably the simplest thing to do is to put another toggle switch in the system and open the power wire to the relay. I know that finding the problem is important to you but you might have a partial short in the wiring harness somewhere and you'll be pulling you hair out for a long time to find that and it may get spendy. Sorry thats all I've got.
Bill