Diagram shows Fuse #23 protecting the direct power feed to the Amplifier. The diagram also shows the Amplifier connected to the Radio at Terminal #4 which is a direct power connection protected by Fuse #8. The diagram shows that Terminal #4 on the Radio is connected to Terminal #9 on the Amplifier which is a connection to the power directly coming thru Fuse #23. So does the power protected by Fuse #23 stop at the Amplifier or is there the possibility the Radio could receive power from the Amplifier &/or vice versa? Clearly the radio is connected to the speakers via the amplifier. Just asking those that have the expertise. Looking at the wiring diagram "makes my head hurt"!