When you say it quits charging, what is the voltage? I am asking because typical alternator behavior is the alt will charge at 13.9 or 14.0 right after the engine is started, and the chassis batteries are slightly discharged. As the chassis batteries top off and their internal resistance goes up a bit, the voltage will usually drop to 13.7 to 13.8 and hang out there.
Richard and Rhonda Entrekin
95 Newell, 390 Ex caretaker
99 Newell, 512 Ex caretaker
07 Prevost Marathon, 1025
Maverick Hybrid Toad
Inverness, FL (when we're home )
(06-10-2025, 02:19 PM)Richard Wrote: When you say it quits charging, what is the voltage? I am asking because typical alternator behavior is the alt will charge at 13.9 or 14.0 right after the engine is started, and the chassis batteries are slightly discharged. As the chassis batteries top off and their internal resistance goes up a bit, the voltage will usually drop to 13.7 to 13.8 and hang out there.
If I don’t turn on the generator and flip the merge switch voltage will continue to keep going down and down below 12 volts. But I never let it go that low
If I were chasing this problem, I would plan a drive that allows me to safely stop when the alt stops working. Stop but leave the engine running, then I am going to use a voltmeter and check voltage at different points between the alt and batteries.
I also would stop the coach and restart to see what happens. That would tell me if it was a “time based”’problem or not.
Richard and Rhonda Entrekin
95 Newell, 390 Ex caretaker
99 Newell, 512 Ex caretaker
07 Prevost Marathon, 1025
Maverick Hybrid Toad
Inverness, FL (when we're home )
And if you trace it back to the alternator, my first shot with the parts cannon would be to put new brushes in it based upon the intial problem you found.
Richard and Rhonda Entrekin
95 Newell, 390 Ex caretaker
99 Newell, 512 Ex caretaker
07 Prevost Marathon, 1025
Maverick Hybrid Toad
Inverness, FL (when we're home )
(06-11-2025, 10:02 AM)Richard Wrote: And if you trace it back to the alternator, my first shot with the parts cannon would be to put new brushes in it based upon the intial problem you found.
I just put a set of new brushes in it. I bought another regulator I’m gonna put that in and see what happens.
When I jiggle the circles wire which goes from on of the brushes to the case of the alternator it starts charging again. I could not get the nut out of the case so I put another wire (shown in blue) from the brush to the top of the case. It seems to be ok now.. maybe that old wire was bad?? Would that potentially be my problems??
(06-12-2025, 11:11 AM)whited44 Wrote: When I jiggle the circles wire which goes from on of the brushes to the case of the alternator it starts charging again. I could not get the nut out of the case so I put another wire (shown in blue) from the brush to the top of the case. It seems to be ok now.. maybe that old wire was bad?? Would that potentially be my problems??
(06-12-2025, 11:11 AM)whited44 Wrote: When I jiggle the circles wire which goes from on of the brushes to the case of the alternator it starts charging again. I could not get the nut out of the case so I put another wire (shown in blue) from the brush to the top of the case. It seems to be ok now.. maybe that old wire was bad?? Would that potentially be my problems??
Given your results when jiggling the wire and installing the additional wire I would put some money on that wire being faulty. I remember my father preaching to us to check the grounds and not just the positive connections. It takes a full circuit to work properly.
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