81 XJ550 Maxim Start Button Ground Wire

So I got a free 81 XJ550 Maxim and I am going through everything on it. I just went through the ignition system test steps listed on here, which is an awesome post! So I got down to the start button being the problem. I took it apart and sure enough the little nipple piece that sits between the button and the spring was warm out. I flip it over and check the continuity on all the wires and get ready to put it back together. While adding dielectric grease to the electrical connection I noticed the the plug end on the bike has 3 pins, yet the the button assembly has 4 wires. There is no connection for the ground wire on the bike side connector. I did a little searching and in another post for a 82 550 someone said that there is no ground on the 81 because the handlebars themselves are grounded, is this in fact true? Now I know what your thinking, did I try to start the bike using the button? No, I had to stop working on it for the night and have not gotten that far!

 

Correct, the start button grounds through the bars. Those little round buttons and the thin plastic flange are definitely not the best design. Good luck with the bike!

 

Thanks! I ordered 2 new ones to replace the horn as well.