I have an older L3710 glide shift that has been running just fine since I bought it a year ago. On cold mornings, I have to let the Glow Plugs turn off, turn the tractor for about 30 secs and then repeat the process again to get the machine to start. No big deal. Last week, I got on the tractor, turned it on, glow plug light went out, I turned it over. Turned the switch off, waited about 5 seconds then turned the switch back on. Lights on the dash came on dim, turned the key to start and they went OUT! I have replaced the key switch, cleaned the batter terminals and chassis side ground lug; check the slow blow fuse in the main power line. Pulled the wires off every relay on the dash and can't isolate the problem. When you turn the key on, the battery feed wire voltage to the B lug on the switch goes to one volt. I got some results by banging on the tab that holds the glow plug timer and relay. That helped for a minute, now it's completely dead. I am totally confused at this. I'm no stranger to electricity, I'm an electrical engineer. This one has me scratching my head. Does anyone have any suggestions?