I started up my 90 cummins normally. Drove it and the trailer across the pasture, so it was running for about 5 minutes. Shut it off, decided I wanted to park the trailer a little differently. I went to restart, and had a bunch of clicking, but no start. The voltmeter shows a huge draw, but that is kind of normal with the intake heater. The battery is a bit old, but has never shown any sign of weakness. Do batteries just up and suddenly die? What could be creating such a huge electrical draw?