Marc, you stated that you have a multimeter.  You DO have the means to measure current draw with that!  You just need some training in the use of your multimeter.  I've never seen a multimeter that didn't gave the ability to measure amps, which is current flow.....

Sent from my iPhone

> On Jun 1, 2014, at 11:39, Marc Perdue <mcperdue@GMAIL.COM> wrote:
> 
> Thanks for all the suggestions! I am about to go out and adjust the belt
> tension.
> 
> Dennis, the load was measured by a clamp that he put around the battery
> negative cable.
> 
> Given the number of responses about the stereo, I realize I left out some
> crucial information. I've been chasing battery/charging/ground issues for a
> long time now. At one point, I realized that there was a problem with how
> Crutchfield installed my stereo. Given that they give a lifetime warranty
> on their car stereo installs, I've been going back to them to get things
> straightened out.
> 
> At any rate, it had been wired so that the subwoofer was always on. When I
> explained this to them, I didn't do a very good job of telling them what I
> wanted. Now, the stereo can only be turned on when the engine is on.
> Sigh... The upside of this is that the stereo is not likely the cause of
> the leak, though I wouldn't swear to that.
> 
> Another thing that it seems I was unclear about is this: I have a good
> multimeter. I'm not scared of electrical issues. In fact, given my
> background in copier and computer repair, I do have some decent rudimentary
> training in electronics troubleshooting and repair. I do NOT have a device
> for measuring current draw. That would make troubleshooting this problem
> significantly easier.
> 
> I do not have power locks/windows or any USB charging devices in my van.
> Honestly, the digital clock is the only thing I can think of that is on.
> 
> How do you test for a change in the current draw after pulling fuses?
> 
> Harold, thanks for the offer of help. I think I'll be able to get to the
> bottom of this. At the very least, I'll adjust my belt and measure what the
> alternator output is then. I may go shopping for something to measure
> current draw . . .
> 
> Marc
> 
> 
> On Sun, Jun 1, 2014 at 10:29 AM, Dennis Haynes <d23haynes57@hotmail.com>
> wrote:
> 
>> If the alternator belt is loose/slipping output can be reduced especially
>> at idle. The set voltage with stock regulator is 13.8v. With a heavy load
>> or low battery the engine may need to be revved to reach this voltage.
>> I am curios how/where they measured that .5 amp drain. If in fact you are
>> draining that much the battery will only hold it a couple/few days. Power
>> locks and a stereo can do this. So can USB chargers and other stuff plugged
>> in even when they are not actually being used.
>> 
>> The alternator belt layout on the Waterboxer is a real bad after though.
>> Belt tension is critical due to the fact that the belt does not wrap around
>> the drive pulley. New belts will stretch and wear into the pulley so they
>> will have to be readjusted shortly after install. Also, the original belt
>> was a custom material for this job. The aftermarket stuff just doesn’t seem
>> to have the durability needed here.
>> 
>> Adjust the belt, get rid of that parasitic load and see what happens.
>> 
>> Dennis
>> 
>> 
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>> Of Marc Perdue
>> Sent: Saturday, May 31, 2014 10:53 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Electrical problem?
>> 
>> Hi all,
>> 
>> I've been experiencing what may or may not be a problem on my '87 Westy.
>> For reasons tied to it running rough, possibly injectors, and its
>> impending painting, I haven't been driving it much. It might sit a week or
>> two without being driven. When I do go to drive it, usually the battery's
>> much too weak to get it started. I plug in the charger, set it to 10 Amps,
>> and let it charge for a few hours, after which I can usually get it started.
>> Once it starts, there's usually a lot of belt squeal. This is odd because
>> I had both belts replaced and adjusted by a reputable Vanagon mechanic in
>> Staunton about 1,000 miles ago. The battery is a Diehard and was replaced
>> within the last year. Thinking I might have an alternator problem, I took
>> it to Advance Auto and had the alternator tested, in the van. It passed,
>> but just barely. Under full load, it was putting out just over 12 volts.
>> With everything turned off, there was still a current draw of about half
>> an amp. Is this normal? I've been going through the van cleaning all the
>> grounds and repairing any connections that look at all iffy.
>> 
>> I'm going to tighten up the alternator belt tomorrow and thought I would
>> give the alternator a spin and see if I could tell anything. Thoughts on
>> what to look for?
>> 
>> Should the battery normally run down to 7 volts or so in a week or two?
>> 
>> Any thoughts on other things to look for? I don't have a way of measuring
>> current draw at home, or else I would start disconnecting things and see if
>> that half amp draw changed.
>> 
>> Thanks in advance for any light you can shed on this!
>> Marc Perdue
>>