driving at night and BOOM! no lights!

So, the other question that begs to be answered, is how was the bike turned off. If the ignition key was functional, that means that it was still getting power, which should not be possible if MAIN is blown.
Clarification is required.

First quick look in the fuse box revealed 3 of the 4 fuses blown. Main, headlight , and signals. The one that was OK.... Ignition fuse, thus why I made it home! Now to figure out why?

Um, this cannot be correct.

You have a short somewhere. Do you have a wiring diagram? There is some commonality between all of them.

Check your diagram AND your actual wiring. If you blew the main fuse, there should be no power to the bike at all. If your ignition survived a blown main fuse, then your wiring is out of order. It should follow like so:

BATT (+) -> 15A FUSE -> R/R joins -> IGN -> FUSE BLOCK (3 x 10A) -> systems

If the 15A fuse was in the right spot, blowing it should kill the bike.

You have a short somewhere. Do you have a wiring diagram? There is some commonality between all of them.

First quick look in the fuse box revealed 3 of the 4 fuses blown. Main, headlight , and signals. The one that was OK.... Ignition fuse, thus why I made it home! Now to figure out why?

Lots of work to be done...thanks I'll get cracka lackin

Sounds like two fuses, lights and signals.

[hjfisk]

Grounds are the biggest problem on these bikes second are the plug in connectors, take them apart and clean them up, remember you are working with equipment that is 31 years young

Look for wires that have the insulation worn, even a little bit of exposed wire can ground out and pop a fuse. I had this issue for a while and it was just bad wiring. Also check the fuse box, I guarantee you popped a fuse. Either the bump jarred it and broke it, or it rubbed a wire somewhere and popped it.

Sounds like ground issue(s) to me. Time to fire up the multimeter and start testing.

Yes this is true, it just happened last night.
First of all, thanks to you fellas who have helped me get my project 1980 GS 550 up and running.
Here's the story. Yesterday I took the bike to work for the first time. 27 miles each way. On my way there I noticed my turn signals were non-functional all of a sudden and I lost my gear indicator lights. No biggie I thought. On my way home I hit a bump in the road, a little hard mind you, and my headlight went very dim. But the very next bump, all lights out! NO headlight or tail light. I acutally rode it for the last mile like this...in the rain....at night. SCARY! STUPID! but EXILERATING!
Anyway, it figures because I did everything to this bike to get it running and rideable. However, I didn't touch the wiring because that was the one thing that worked when I got it. All lights were functional. I havent' had a chance yet to look at it, but it dosn't seem like a fuse problem...any ideas?