Sounds like the shop used the kitchen sink approach.
To me it sounds like a partial shorted PTO clutch that is over taxing the charging system. I have seen clutches to pull over 15 amps and still operate. Using an ohm measure the PTO clutch coil to see if the resistance is 1.7 ohms or higher. IF below 1.7 ohms it needs replacing. Normally these clutches pulls 3-5 amps with 7 amps being the max. This is why I fuse these clutches with a 7.5 amp fuse. If that fuse blows that I know sure there a PTO clutch problem. Also note sometimes the resistance is fine but the bearings are shot and the clutch is shorting out while operating. Kinda rare as usually it is the coil (field windings) that is the problem. I think in the 15 yrs I have seen only two that was shorting out during operation.