A diode is a one- way valve for current (electricity). This is a basic explanation I think:
https://learn.sparkfun.com/tutorials/diodesYou cut the brake light wire, put the diode in- between the wire where you cut it and then solder it in on both sides. Or you could use crimps on both sides. The cover it with heat shrink tubing or worst- case, electrical tape (but do a good job 'cause you kinda' need that brake circuit).
Now where to get a diode.... well, you can get them by the onesies or twosies at Radio Shack for a reasonable price. But RShack went belly- up and a lot of stores are closed. The good news is that they are less than a penny a piece; the bad news is that you gotta' buy a bunch of them and pay shipping. Tell you what, I will send you a diode. Just send me you contact info. (name, street address, etc.) and before you can count how many protons there are in a Couloumb, it will be in your mailbox.
By the way, as a diode is a one- way device, it must be installed facing the right way. If not, nothing bad will happen in this instance but the brake light will not work. The right way is with the band on the diode facing the brake light side of the circuit, not on the side going back into the bike's harness.
All C-14's are the safest motorcycles possible as they are protected by the security envelope and everlasting goodness of KiPass.
Brian
I knew it was something crossed or back fed somewhere along the lines and I knew someone on here would be like Oh Yeah I know this one! Ha... When everything was working properly I had the safest C14 a$$ on the road! The whole butt end of the bike was flashing when I hit the brakes and directionals half the bike blinked. Now for the $64,000 question. What's a diode and how would one install said diode?