First thing is first

Before any electrical modifications please be aware of these things

Battery

Get your motorbike is up and ready, Check and maintain it for proper voltage.

1. check the battery level when engine off that is 12.3V or above.
2. check the battery voltage when engine running that has to be battery volatge + 1.5 volts,

Example: Your battery level at engine off is 12.3V, then engine on (Charging voltage) will be 13.8 or above.

If your bike is out of battery connection, first heck for fuse. If fuse is blown, then check for short circuits in wiring harness. Please don't bypass fuse, It may spoil your good battery.

Contacts

Keep all electrical contacts proper and good, make sure every cut or joint has insulated. Make use of metal connectors while joining wires to devices like Horns, relays, etc., please avoid skinning wire and twist connections.

Before doing any project with Microcontroller or any sensitive 5V device, Get pure 5V DC circuit first.