Date: Sat, 17 Jul 2010 19:50:56 -0500
Reply-To: Tom Hargrave <thargrav@HIWAAY.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Hargrave <thargrav@HIWAAY.NET>
Subject: Re: Alternator output
In-Reply-To: <002901cb2610$5a118160$0302a8c0@ALFRED>
Content-Type: text/plain; charset="us-ascii"
All depends on the condition of the battery.
If the battery is known-low then 13 volts is OK until the alternator charges
enough to bring the system up to at least 13.8 volts.
If the battery is completely charged then 13 volts is low and needs to be
investigated.
Charging systems seem to be the least understood of all automotive systems.
Alternators don't put out voltage, they put out current. The voltage you
measure is a result of the load put across you alternator at the time you
measure. So, for a given alternator output current, a greater load like a
under charged battery will result in a lower voltage. And a lesser load,
like a fully charged battery will result in a higher voltage. The voltage
regulator acts like a high limit or not-to-exceed switch. Once your system
voltage reaches your regulator voltage the regulator will start turning your
alternator off.
The designers of the roll around charging system analyzers used by the car
part chains & that we all seem to mistrust understand this. They work by
load testing the static battery then testing the alternator under different
load conditions. Used correctly they tell the operator the exact condition
of your charging system. If you are not sure I suggest you pull into a local
AutoZone or similar place and have them test your charging system - it's
free.
BTW, alternators don't fail gradually. The do their job until a component
fails. And usually it's the regulator or internal brushes or a diode in the
internal diode bridge.
Tom
www.towercooler.com
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
alfred bagdan
Sent: Saturday, July 17, 2010 7:30 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Alternator output
Hi all,
I put a voltmeter across the battery and revved the engine at 2000RPM+ and
get a reading of only 13.0 Volts.
Should I be worried or will the alternator last a bit longer?
Thanks,
Alfred
85 Vanagon
----- Original Message -----
From: "Shawn Wright" <vwdiesels@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, July 17, 2010 5:42 PM
Subject: Two failed tires... :-(
> Last week I found a bad gash in one of my Yokohama 370s up front, so I
> planned to swap my BFG ATs from rear to front and put my Conti spares
> on the rear. I figured this would be a good chance to try the BFGs on
> the front, as I've never tried them (I only have 2). I was shocked to
> find a horrible bulge about 1" diameter in the tread of a BFG, where a
> previous patch was made (a proper inside patch done at Kal Tire). It
> is so bulged that the steel belts are showing and worn through,
> exposing the layer beneath. Ack.
>
> So that makes 2 bad tires in 2 weeks, meaning I am definitely looking
> at a full set, probably with new 15 or 16" wheels.
>
> I'm currently reading this thread:
> http://www.thesamba.com/vw/forum/viewtopic.php?t=203519
>
> trying to glean as much info as possible on wheel options. I hadn't
> planned on this now, but it seems I have no choice.
>
> I was able to return the EV 15" wheels I bought as they were not a
> good fit (ET55), so I'm shopping for options. I'm considering 16x7
> ET35 wheels from tirerack (same as GoWesty sells) with BFG AT
> 215/70R16.
>
> --
> Shawn Wright
