When you turn the key to run, waiting for the glow plugs... The volts gauge pops to the normal spot. Stays there while the GPs are cycling. When they have finished, the GP controller starts clicking. With each click, the volts gauge reads a little higher. Finally, when the GP controller clicks off, the volts gauge pegs to the top of the gauge. Is this a gauge problem, or a voltage regulator problem, er whut? I don't want to put too much time on it with it pegged like that. Need to get it figured out. How to test this???