I have an M936A2 that when I start it pegs the voltmeter for exactly 5 minutes then drops down to normal. I have measured with a voltmeter to confirm and it goes to ~34 volts for the 5 minutes then drops back to ~25. When I got the truck the wire to the alternator was disconnected and now I know why. I know there is an adjustment but before I try that I wanted to get peoples thoughts on why it would be so high. It does have two 12v batteries that are undersized in my opinion and I plan on upgrading to group 31's.