Just joined the site hoping someone here will have an answer for me, I have a 1989 E350 28' Fleetwood Jamboree class C motorhome with a 460 efi. I decided to fix a squeal I've been getting at startup. I figured out it was the alternator, so I started digging into it. I got to the point where I realized that the plug that houses the 2 heavier gauge black wires and one white wire isn't actually a plug. It looks like a plug but is molded into the alternator case. As I researched what I was looking at, I found out that I currently have a G2 alternator, and swapping to a G3 would be a wise thing to do. Currently, I have the old alternator/harness laid out trying to figure out where everything goes and what it does before I move forward. I have the 2 black wires and one white one coming out of the alternator, 2 wires going into the plug that came out of the regulator on the back of the alternator, 2 heavier wires that were butt connected to the next harness (white arrow), a round plug with 3 terminals (black arrow), and finally 3 wires that connect to the starter solenoid. The G3 swap looks easy enough. I understand that the current harness would be replaced by the G3 wiring setup. My problem is that I don't know what to do with the round plug and the 2 bigger wires that were connected to the next harness. I'm guessing that the wires have something to do with the house battery. I understand that the swap will lose function of the ammeter, which is fine. I'd just like to retain the rest of the factory functions of charging both the house and cab batteries. Hopefully someone here can tell me what I'm looking at. Thanks!