I am working in my basement where the wiring is from the early 70s. I am replacing a couple of fluorescent lights with new ones so I can put in LED bulbs (the others are original). I am not new to wiring and have done quite a bit. I learned from my dad (and I also know his style). I got into mess from right at the beginning.
I should clarify this. The two wires heading down out of the picture is to the light fixture.
Not knowing what the heck was happening there, I started tracing wires. One set is the hot wires. The other 14-2 goes to a switch. The 14-3 I was confused about for quite a while, but finally figured out that it powers the outlets . The red goes to a switch the power the top outlet, the black keeps the bottom outlets hot full time. I matched the wiring back up and tested it. My GFI breaker (in a separate box flips and separate circuit). I do some more looking, and "properly wired" the switch for the light (I really didn't like how they wired it). (The green tape is labeled switch). Tried again and it still blows the GFI breaker. All of the grounds are wired correctly, all of the commons are linked correctly. Could these new ballasts blow an older GFI breaker?
If you want I can upload a picture of how I currently have it wired, I can. I am at a loss of what is happening. I'd hate to call an electrician for something that could be a simple fix.
On the other hand, I discovered that the outlets are all twisted and soldered wires then covered in tape. I am going to fix that crap right away and fix the open grounds that I discovered as well in this series of outlets.
Update: Added more pictures and added my second light without any issues.