I don't see any indication of a "LOAD" terminal on the regulator in the wiring diagrams. I think you have a replacement regulator and the L was never connected on your 147. I see 2 differences between your diagram and one for a 147:
- regulator G connected at the solenoid rather than the A terminal of the generator. Doesn't matter electrically, just connecting at the other end of the same wire.
- PTO safety starting switch doesn't exist in the 147 diagram.
Your light wiring isn't shown in either diagram. It should have an in-line fuse between the ammeter minus and the light switch. The other light switch terminal can have up to 3 wires. One is the wire in the harness that goes to the headlights, the other 1 or 2 go to the tail lights. I guess the 147 tail lights always came in pairs with 2 separate wires.