Date: Sun, 1 Jun 2014 11:59:31 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Electrical problem?
In-Reply-To: <CAEwp_cSvky5-D-UiYYbCM9TH_E1oU5LpjLiVRCFvspZd4Dz=iQ@mail.gmail.com>
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Current measurement is always a challenge as the meter has to in series with the circuit. Inductive clamp on type get around this but DC is difficult especially at lower currents. These meters can be horribly inaccurate.
There are meters designed to plug into the place of fuses. I have one and it is awesome for finding these types of loads. Your multi meter probably has a current function so you could do the same with that. Since you looking at a small load place this meter between the battery and ground cable. Be careful not to turn anything else on. Confirm the .5 amp load and then start disconnecting stuff until that load goes down or disappears.
Dennis
For the stereo control the key in ignition contact could be used to trigger the head unit, which should also trigger the sub-woofer.
Another possibility is that alternator itself has a bad diode and is becoming a load. I would check this due to the poor output.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Marc Perdue
Sent: Sunday, June 01, 2014 11:40 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Electrical problem?
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
>
