I have a head scratcher here. Ingersoll air compressor with Ingersoll Rand brand diesel engine (made by Isuzu not Yanmar). It will start and run as long as you hold the key on start. I tried a new key, relay, and then started checking every wire. Turns out I do not get 14.7 volts from the alternator...it does not output anything just shows battery voltage. So I decided to put a jump wire on relay pin that is fed by the alternator (hoping that would fool the relay into keeping the fuel shut off solenoid on when I let go of the key and let it go from start to run) but the fuel shut off solenoid closes right back up the second you let off the key from start to run. If I bypass the fuel shutoff solenoid the machine works beautiful EXCEPT of course the alternator is not charging. So I have a replacement alternator coming - however I am unsure if that will help me figure out when the fuel shutoff solenoid won't stay on once it starts. Its the only thing I can tell would get power to the relay after the key is switched to run. Any ideas?