No lights!!

You said the brown wire was heating up? Since the electrical system is quite simple and there is nothing but lights and a horn and they all get power from the brown wire, the brown wire goes to just about everything on the bike. If you disconnect the horn, tach and speedo lights, neutral light, dimmer switch, key switch, front and rear brake switches, regulator, turn relay and turn signal cancel unit it should be completely isolated and read as an open circuit to ground with the ohmmeter. If that checks OK then try connecting everything back one at a time until you get a very low resistance to ground and that will be the problem. Since you said you were welding right before the problem I suspect you accidentally melted the insulation on a wire somewhere or caused something to short out. For the purpose of troubleshooting you can leave the battery disconnected or replace it with a big capacitor so the lights don't flicker and it will make troubleshooting easier since there won't be any voltage unless the engine is running.

If you power the system with the regulator disconnected nothing is going to happen since all power goes through that when it's running. Might help with ohming out the wires though.

You can discard the flasher canceling unit if it's shorted and just cancel the turn signals manually each time. Mine hasn't worked in over 15 years. I think you need to ground the wire going from the turn signal flasher to the flasher canceling unit to get the flasher to work but it's been so lone I can't remember for sure. You can also replace the turn signal flasher with a cheap two pin thermal one from the store if you connect the two pins into the plug correctly.

I don't think that's true, but I'm not positive. I didn't try it with the engine running, because it's been raining cats and dogs for three days. My garage is just too cramped for easy starting.

Anyway, I pulled the unit and I don't get any blinkers. Not even steady on. I also tried jumping the red/yellow and the green/yellow as miker suggested. Still nothing. I do have a tail light and brake light that I did not have when the unit was shorting.

It's rebelling because some people shouldn't be allowed to own an SR!

After what he did to it, it wants out! If it could start it would probably run away!

Steve, in my defense, I told you I was a moron from the start. You gave me just enough "tough love" to go out and give it one more shot today. I was checking my CDI connections and getting strange results. But I guess that's to be expected when you CONNECT YOUR CDI TO THE FRIGGIN LEFT-HAND SWITCH UNIT!!!!! (horn,flashers, highbeam) The connections are the same shape,but the connectors and wires are different colors. I really can't explain what I was thinking when I made that connection. You are right, I really don't deserve to own an SR500. To think that I made all these blunders, sort them out slowly, and it all still works is simply incredible. In your honor, I started it up, and I went into the house to give it a fair chance to run away. I would have totally understood if it was not there when I returned. Thanks again, John.