I have a tc30, like a 2005. The glow plug light stays on and drains my battery. I can not locate a relay or timer. When I unplug the harness from the glow plug bar I still get like 10 1/2 volts. The ignition is unplugged so I have ruled out an ignition problem. I pull the 5 amp fuse then I lose the volts. I have had this since new and I'm not sure what to do next. I stopped at the dealer i bought it from, bought they no longer handle new holland. My work schedule is rough so I haven't been able to contact the closest dealership to talk to a mechanic