Another generator post

[Tom Lins]

> On my 73 I've owned since this May, I have a Generac Guardian RV generator that had been working fine. Recently it wouldn't start and seemed to be
> the battery which looked kinda old. So got a new battery. charged it and gen started fine, but after a few hours died. The battery was discharged,
> so I jumped it and started right up. Disconnect the jump box and after about a minute the gen stops. Just to be sure I checked the fuel lines,
> filter and pump - all OK. Tried jumping again, started, this time left the jump box on. The gen stayed running for about 10 minutes so I
> disconnected the jump box and within a couple minutes the gen stopped. Next, put a trickle charger on the battery overnight. It started right up and
> kept running so after about half an hour I turned on the AC which worked fine. The fridge was working etc. This was yesterday, I shut it down then
> went out today and no go.
> So it is providing power to the house fine but not charging its own starter battery. How can this be? There my also be some parasitic drain that
> is probably related, but not sure on that one.
> Waddaya think?
>
> Shane

Sounds like your converter is not plugged into an AC outlet or it is not working. If it works like the original Onan it only makes AC and does not
make DC to charge the battery.
--
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, FI-Tech EFI, Aluminum Radiator Quad-Bag Suspension
Manuals on DVD
GMC Dealer Training Tapes
http://www.bdub.net/tomlins/

 

[Tom Lins]

What is the model number? So I can find the manual.
--
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, FI-Tech EFI, Aluminum Radiator Quad-Bag Suspension
Manuals on DVD
GMC Dealer Training Tapes
http://www.bdub.net/tomlins/

 

[Bruce Hart]

Tom, On some 73's the generator had it own separate battery. When the
generator is running take a volt meter and see if you are charging the
battery if not the voltage rectifier most likely is bad. M.W.A.G.

On Sat, Aug 24, 2019 at 6:36 PM Tom Lins via Gmclist <

> What is the model number? So I can find the manual.
> --
> Tom Lins
> St Augustine, FL
> 77 GM Rear Twin, Dry Bath, 455, FI-Tech EFI, Aluminum Radiator Quad-Bag
> Suspension
> Manuals on DVD
> GMC Dealer Training Tapes
> http://www.bdub.net/tomlins/
>
> _______________________________________________
> GMCnet mailing list
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--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class

 

[Tom Lins]

> > > On my 73 I've owned since this May, I have a Generac Guardian RV generator that had been working fine. Recently it wouldn't start and
> > > seemed to be the battery which looked kinda old. So got a new battery. charged it and gen started fine, but after a few hours died. The battery
> > > was discharged, so I jumped it and started right up. Disconnect the jump box and after about a minute the gen stops. Just to be sure I checked
> > > the fuel lines, filter and pump - all OK. Tried jumping again, started, this time left the jump box on. The gen stayed running for about 10
> > > minutes so I disconnected the jump box and within a couple minutes the gen stopped. Next, put a trickle charger on the battery overnight. It
> > > started right up and kept running so after about half an hour I turned on the AC which worked fine. The fridge was working etc. This was
> > > yesterday, I shut it down then went out today and no go.
> > > So it is providing power to the house fine but not charging its own starter battery. How can this be? There my also be some parasitic
> > > drain that is probably related, but not sure on that one.
> > > Waddaya think?
> > >
> > > Shane
> >
> > Sounds like your converter is not plugged into an AC outlet or it is not working. If it works like the original Onan it only makes AC and does
> > not make DC to charge the battery.
> I was just going over the schematic and it appears this unit has a winding just to charge the battery. This goes to a rectifier then to battery. I
> am not an elekchicken but I have a meter, just need to know what (how) to check these components out. ie on the rectifier which has three plugs
> (case probably ground) what do I look for.
> Thanks for the help.
> Shane

I believe I found a wireing diagram.
Check and see what the voltage is at the battery with the generator running.
If you are not getting at least 13.5 volts it is not charging.
You need to measure from case ground to the side of the rectifier that goes to the battery.
If that also is low check each of the other two legs of the Rectifier.
If the voltage is low on the input side of the rectifier the charging winding is bad.

JMHO

--
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, FI-Tech EFI, Aluminum Radiator Quad-Bag Suspension
Manuals on DVD
GMC Dealer Training Tapes
http://www.bdub.net/tomlins/

 

[Tom Lins]

Check the F1 fuse also, it looks like the power goes thru the fuse to get to the battery from the rectifier.
--
Tom Lins
St Augustine, FL
77 GM Rear Twin, Dry Bath, 455, FI-Tech EFI, Aluminum Radiator Quad-Bag Suspension
Manuals on DVD
GMC Dealer Training Tapes
http://www.bdub.net/tomlins/