Alternator is bad, given everything you've said.  Test under load with the
headlights on and heater fan on, should be over 13.5 minimum, looks like
yours isn't.

Stuart

-----Original Message-----
From: Dennis Jowell [mailto:dennisjowell@gmail.com]
Sent: Friday, July 15, 2016 10:47 AM
To: Stuart MacMillan
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: Checking output of alternator.

Just got back from a test ride. I checked the output of the alternator at
idle its 14.1 at the stud positive and grounded on engine frame and stays
there at high rpm. Yesterday I installed a new battery, changed it to 13.5
volts, drove 75 miles, new battery is now at 11.9-12.3. Engine is at running
temp. I have no idea where to go now. I thought the 5 years old battery was
DOD so,I changed it. All cables and wire are tight on battery and
alternator. All have dielectric on them.
Help! Any thoughts where or what I should look at?

Dennis Jowell
Scotch Hollow Farm
Newbury, Vermont

> On Jul 14, 2016, at 12:40 PM, Stuart MacMillan <stuartmacm@gmail.com>
wrote:
>
> You need a high end tester/charger for this.  Parts stores and Sears
> repair shops will test it for free. Should have a minimum 75% output
> with headlights lights and heater fan on. Alternatively, you can
> measure the voltage at the alternator under this load.  Ideal output
> should be 14.2 volts, but 14 is typical. If 13.2 or less I consider it
junk.
>
> I've replaced two recently that tested 25% with Bosch rebuilds from my
> local supplier (who could also switch the pulley for me), one of which
> tested at 50% when installed.  They replaced it. It's just the poor QC
> of rebuilds, so test your "new" alternator too.
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> Behalf Of Dennis Jowell
> Sent: Thursday, July 14, 2016 9:11 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Checking output of alternator.
>
> After driving my Westy to Middlebury, Vermont area decided to visit a
> historical site in town. Westy started slow but it started back to the
farm.
> Stopped at another state park and had some lunch. Westy now won't start!!
> Ugh! I used the aux battery to get it going and got home. Main battery
> is new. I suspect the alternator is NG. Once again trying to
> understand the Bentley test procedures on Pg. 27.18. What is " connect
> alternator/regulator tester" ?? All I have is my digital ohm meter. Is
> that what they are saying ?
>
> Dennis J
>
> Dennis Jowell
> Scotch Hollow Farm
> Newbury, Vermont
>