I think I ran the 300SD too low on fuel, cranked it a lot and it wouldn't start. Filled it back up, ready to follow the directions on how to crank it to bleed. However, it turned about 1 1/2 times, then the battery would go no mo', it would just click. Recharged the battery (at Autozone, it was brand new anyway), but the same click is all I get. Can't hotshot it, either. Glow plugs warm (light goes off, anyhow), all other functions seem to work, but when you try to start, it gives one click from the (?)regulator? (small black box in the front driver's side of the engine compartment). Is this a regulator problem, if that's even what that box is? Or is it something else? I've no idea, and it has been sitting for a while and I would kind of like to get it started.