Front Alternator 8V92

[gregory O]

I dont know, may be that is where they are failing more often in motorhomes, by
being run with the battery bank turned off? or up against a battery bank being
charged via a shore wire at a higher than 13 amp? If the rectifying diodes are
that burnt it would suggest your claim. I have a battery/alt test device that
make a heat coil load I think it was about $30. from harbor freight not a very
good instrument but one more test to help make a decision. I was unaware that
running an alt without a load would cause harm to the alt
Greg of Tim&Greg
94ptca

--- In WanderlodgeForum@yahoogroups.com, "Donald Watson" wrote:
>
> I appreciate your posts Greg, especially since you have a pretty diversified
> experience with heavy equipment.
>
> That being said, did you really mean, "Check the output when output wire is
> disconnected from bus batteries." ??
>
> Without a battery or batteries to act as a load, I believe the rectifying
> diodes would burn up in an instant. Greg's suggestion of lifting the
> alternator output cable on both ends , checking continuity as well as
> resistance to ground is a reasonable one. I have a friend who drives over
> the road with a 60 series Detroit. He goes through alternators quicker than
> he should and I wonder if it is simply the quality of the rebuilds that is
> questionable as Greg suggested.
>
> Donn
> '76 FC33
> South Kingstown, RI
>
> From: WanderlodgeForum@yahoogroups.com
> [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of gregory O
> Sent: Tuesday, October 13, 2009 9:12 PM
> To: WanderlodgeForum@yahoogroups.com
> Subject: [WanderlodgeForum] Re: Front Alternator 8V92
>
> alternators require many working parts any one part that fails will not
> allow it to work. when a bearing goes out it still pumps amps but the heat
> can screw the windings and vr. if the prior rebuild didnt repair the bearing
> or other cause for resulting failure replacing a burnt electrical component
> will be short lived, like in your case. The other possibility is something
> is burning out the electronics and replacing the alt will only prove that
> point with a third failure.
>
> Check the output when output wire is disconnected from bus batteries. I
> would then take the alt to a good rebuilder.
>
> one other test is to remove both ends of the charge wire, insulate the
> battery end, then check for continuity with ground at the alt end. there
> should be no continuity, if there is, 'continuous path' will show a ground
> fault which will always demand amps.
>
> You can usually find a referral of a local parts re builder from a local
> salvage yard. WHen ever I am forced to buy a Pepboys reman alt or starter I
> drop it off at my favorite rebuilder in Riverside Ca. they ship
> http://riversidealternatorstarterac.com/
> Greg of Tim&Greg
> 94ptca
>
> --- In WanderlodgeForum@yahoogroups.com
> , "SteveQ" wrote:
> >
> > I had the front alternator rebuilt in 2007 right after buying the coach,
> and have about 25,000 miles +/- since then. After testing it today it is
> dead again, there must be an underlying problem. Any ideas?
> >
> > Steve Quandt
> > 1993 PT40
> > Iron Mountain, MI
>