As for the switched question. You can switch them and it will still work fine.

The blue and green (yellow in your case) generate a magnetic field inside the alternator's rotor. Reversing the wires reverses the direction of the field but it doesn't effect the way it works. The rotor is rotating and the rotating magnetic field "Drags" electrons along the coils along the outside of the alternator creating electric current in those coils. The rotating field creates alternating current that cycles from positive to negative, hence the name alternator. A rectifier bridge (set of diodes) at the end of the coils "directs" (not the best word here) the alternating current to push the positive current to the output terminal and the negative current to alternator body (engine ground).

The blue wire gives energy to the field coils in the rotor and the voltage regulator. This is the reason to check for voltage at the blue wire. It actually splices into the "Run" portion of the main harness inside the wiring bundle along the passenger side valve cover. You could have positive voltage to the terminal on the voltage regulator and still not have voltage to the alternator if the wiring is bad so check for voltage at the regulator AND the alternator blue wires or check either and then check for proper continuity between the two terminals.


The green wire is a ground passing through the regulator. The stronger the ground connection the more current flow, the stronger the field strength, and the more current output. This is the reason to check the Voltage regulator for a good ground.

Lastly there has to be a good circuit from the Voltage regulator to the alternator and back with no breaks or shorts or nothing works.

I hope that helps because for me understanding how it works helps me to see the problem more clearly.