I sent you a email with some jpegs of the wiring diagrams, hopefully they will help you out.
The silver canister is the horn relay. The power wire is supposed to go to it - it is used as a central power location. Don't worry about it.
The thing you are concerned about is the voltage regulator. Keyed power needs to run to the voltage regulator to turn the alternator on, this normally comes in a brown wire running to the regulator. The white wire is generally used for the generator light. It is quite possible that someone played around with the wires.
Generally speaking, there are two wires that go out of the voltage regulator to the alternator. The two wires coming in to the regulator are for keyed power and the generator light.
