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 
>