L3 MEP-805B; voltage regulation problem

I have an 805B 30Kw that will not properly excite and stay engaged; if the safety reset or battle short is held closed the generator produces ~350v on all lines instead of 208 as it is set up for, thus producing an overvoltage condition and disengages the contactor. This is the computer based model and I have only previously had steam gauged models so I don’t even know where to begin other than testing the transformer at T1 as described in the manual which is within the parameters. I started looking for voltage regulation parts from GAC but cannot find anything even close to what this unit has. Any help or ideas? Thanks to anyone in advance that might be able to help me out.