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Alternator problem - maybe

We are trying to get our '86 Grand Villa road worthy and took it to the local Cummins shop to troubleshoot some issues we have with starting and charging.  At this point they have 60 hours involved and have installed a new start battery, starter, cable from battery to starter and alternator (x2).  I sent them to information on Foretravel alternators from this site but they are still stumped and can't get it to charge while running.  Seems like there is nothing else that could prohibit charging/powering the GV other than alternator.  Thoughts I can pass on?
James Kester
1986 Grand Villa, 29'
Build #2662
F.E.D. RB

Re: Alternator problem - maybe

Reply #1 –
James,

You need someone who is familiar with motorhome wiring.

A very good place to start troubleshooting is the battery isolator.  There you can check for voltage IN from the alternator B+ terminal and voltage OUT to the two battery banks.

Yes, this assumes no one has modified the wiring.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Alternator problem - maybe

Reply #2 –
Quote from: jkester –
We are trying to get our '86 Grand Villa road worthy and took it to the local Cummins shop to troubleshoot some issues we have with starting and charging. 
James Kester
Good Morning Mr. Kester,
It sounds like your new-to-you Grand Villa is road worthy.  For short distances you can run the chassis on the battery.  For longer distances you can run the generator and a power converter such as the Progressive Dynamics 9260 or larger 3-stage battery charger and 12v power supply for house electrics.  I have two installed, one for the house battery and one for the chassis -- to maintain the chassis battery while parked.

It's your decision but if you have "mechanical skills" you can learn what you need to know to trouble shoot the 12v electrics.  Or you can learn what you need to know and teach the unwilling students at Cummins while you pay them by the hour.
The third alternative it to find an automotive/truck electric repair shop, someone who is a specialist in the field.

What is your pleasure?  I'm willing to answer clear concise questions and teach the concepts involved.  The rest of us here can describe everything you need to know about your house and chassis.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Alternator problem - maybe

Reply #3 –
Also, what is the brand/model of the alternator?
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Alternator problem - maybe

Reply #4 –
What is the history of this coach? Did you own it when this "alternator" problem started? What other issues did you want this shop to fix? What engine is in your coach?
1993 U225 Build #: 4285
500 Watts Solar
Honda CRV AWD
Former 1981 Foretravel Travco
Retired, Full Time Off Grid Snowbird

Re: Alternator problem - maybe

Reply #5 –
Note that James' coach is a 29' Front Engine Diesel and so things might be arranged and located slightly different from what most of us are used to.  The specs sheet does show that model had a battery isolator and 75A converter/charger, so those items should function the same as newer models, assuming (as Brett says) that everything is still stock.  On a 37 year old coach, what are the odds of that being true?

Media [ForeForums Foretravel Motorcoach Wiki]

As Peter said (above) we definitely need info (photo and/or make/model) on what kind of alternator is "stumping" the shop techs.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Alternator problem - maybe

Reply #6 –
Quote from: Chuck & Jeannie –
The specs sheet does show that model had a battery isolator and 75A converter/charger, . . .
Yeah, about that 75A converter/charger.  Chances are pretty good that if still original it's a harmonically regulated transformer aka battery boiler.  Second, what type of battery isolator?  Cole-Hersee continuous duty relays?  Nothing can be done until we have the basic information.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Alternator problem - maybe

Reply #7 –
Thanks for the comments. I will be picking it up on Monday and start troubleshooting myself. Much of the wiring has been "modified" so I will start with the original wiring diagram and see what has changed.
We picked the '86 up last month knowing it was in bad shape. No history is available. No generator, brakes leak, air doesn't hold, roof antenna leaks.. Lots of issues but I have time to go system by system. It's a 29' model and we haven't seen any of them still around so we hope we can salvage it.
I'll add info next week once we get it home.
It was at Cummins for sluggish starting and fuel pump leaking internally. Other than the charging issue they got that taken care of.
James




1986 Grand Villa, 29'
Build #2662
F.E.D. RB
 

Re: Alternator problem - maybe

Reply #8 –
Welcome, looking forward on your progress.
Richard & Betty Bark & Keiko our Golden Doodle
2003 U320T 3820 PBDS
Build # 6215
MC # 16926
2016 Chevrolet Colorado 4X4 diesel