c0ke,
1. The ant rem wire is only used if you have an ant that is a power electric ant that need to go up when you turn on the radio, not used
2. You hook up the red wire to the accessary fuse that only comes on when the motor or
key is on, that will let the radio come on when the motor is running. The yellow wire is also hooked up to 12 volts that is always on , this is to keep the radio's power backed up for memory purposes. That way you won't have to reprogram it every time you turn it on. This is taken care of when you plug your radio's plug into the Kubota's plug.
3. The black wire on the plug is already hooked up to ground. The Kubota's plug already has the 12 volts constant, 12 accessary. and the ground connected in the plug and when you hook up the radio's plug to the Kubota's plug that will complete the circuit.
The Kubota's plug has all the power and speakers already connected to it.
Randy