I have a Model 3 wiring diagram. On the print the triangle with the letter P inside, is that the same as ground? is there actually a grounding bar that is used? On the starter it shows a grounding symbol, so I wondered what the difference was.
It shows something that looks like a rheostat labeled lighting coil that goes in to the voltage regulator. Is that the winding from the engine? Also why would you have an inline fuse off the regulator instead of putting the fuse holder in the panel, any reason? Also not quite sure about the relays. I would assume R3 is for the starter but not quite sure about R1 & R2. Are these special relays?

Thanks for any info