Maybe an alternator problem

[wal1809]

I think I might be developing a problem witht he alternator.  I fired the bus up this evening to back it into the barn and while waiting for air pressure I could see the headlights were bright dim bright dim, rapidly.  Like bright to dim and bright in 1 second revolutions. The voltage guage needle was bouncing from a range of 13.5 to 14 volts as fast as the lights were dimming and regaining.   Yall have any idea what might be happening.

[luvrbus]

Wayne,the charging relay in the rear electrical panel change it your problem will go away and remember that is a 6 volt relay not a 12 volt strange huh

good luck

[wal1809]

Thank you Clifford.  ?I am guessing the rear E panel is up above the engine compartment behind the plastic-ish panels?  Woder why they used 6 volt instead of 12.  I guarantee you I would have used a 12 because I had no idea.

[Tony LEE]

It is supplied from a single diode off one of the three phase legs of the alternator - so it is approximately half the voltage of the nominal output of the alternator. My MC8 is 24V so the relay is 12V.

MCI's also have a pressure switch in the system so if that was not closing cleanly, it could result in the alternator cycling on and off. Regulator also causes this problem occasionally in MCIs and the 'cure' is to turn the headlights onto low beam to provide enough load to stop the system hunting

[JohnEd]

Now that is what I call  a "mouthful of information".  Thank you Tony Lee.

John