Voltage regulator and alternator questions

[prg machine]

I am using the stock alternator external regulator for a 69 engine. The alternator was rebuilt by a local reputable shop. I asked if i needed a new regulator and they said try the original first it might be fine. The system shows charging............the regulator is getting real hot in a part that is on the outside of the regulator box. It looks like a small firecracker about the same length. it is a coil of wire around some type of fiber. I looked inside the regulator and it "appears" fine. The alternator is geting quite warm as well and wants to slip the fan belt....................I have shut it down and will take it all in to the shop. I was wondering if anyone might have any ideas oin this.

The wire harness is stock and in very good shape. Everything seems to work in the system, however front headlights, horns, and turn signals aren't in the truck yet. There is a small ground wire that comes out of the harness at the voltage reg. area and i have that grounded to the core support. there is also a small hookup tab for like a "faston" electrical connector on the "back" side of the regulator (towards the core support).. I don't remember anything being hooked to that before................what is that connection for??



Once again, thanks for all of your help.