Hi Don,

Did you get any good advice via pmail?  I've got almost the same setup
and symptoms. If my van sits for one day, the coach battery is really
low.

I have found that if I disconnect the negative terminal of the aux,
leaving the battery ungrounded, I can read voltage between the pos
terminal and chassis ground. This could only be if a grounded
appliance is drawin that current.

You have the advantage with your terminal block as you can pull fuses
one at a time till you get close to 0 volts between the + terminal of
the coach battery and the chassis with the battery ground
disconnected. My setup has a multiple spade terminal with fused wires
going off in all directions. I run the interior lights, stereo, a
small subwoofer and a mobile ham radio off the coach battery.  I
really need to sort this out.

What did your re-test show with your stereo fuse pulled?

Anyway, give the above a  try. I'd be interested to know what you find.

Good Luck,
--
John Meeks

'91 Multivan, '85 GL bits
Northern Michigan
KC8ZFN

Vanagon Rescue Squad
http://www.vanagonauts.com/Vanagon_Rescue_Squad74.htm

On 11/4/07, Don Hanson <dhanson@gorge.net> wrote:
> I am an electrical dunce.
>
>   Can someone give me some instruction on how to trace down a fault with my
> aux. battery that's causing it to go down in about 24 hours?  I have a
> simple Radio Shack multimeter with scales for DCV, Ohm, DCA and ACV.  My
> batteries are <2mos old and have never been run totally flat, but close on
> the coach battery just recently.
>
>   My van was sitting undriven for 2 days and I noticed as I passed my stereo
> was 'beeping' at me, signifying low power.  Took my meter (that I am just
> learning) and tested the Aux. Batt. (which powers the stereo independent of
> the ignition switch) and got 11.4 volts.  Tested the vehicle engine batt and
> got 12.94v.  Started the van and the main battery read 13.9v, running.  Went
> to the coach battery, 13.8v.  So it is charging (new alternator also)
> Checked the function of the solenoid I am using..a canister type...that is
> working also..
>
>   So, I put my battery charger onto the aux battery and left it overnight at
> 2amp setting..Tested in the am at 12.7 volts..the aux battery was 'isolated'
> for that reading.  Drive the van about an hour and still have a good reading
> at the aux battery.  Park it and re-test that aux battery in the
> evening...about 12.3 volts in just 4 hours of sitting..The vehicle battery
> was at about 12.8.  Re-started and again got good charging readings at both
> batteries..
>
>   So, something is drawing some juice and making that coach battery go flat,
> but I don't know how to run down that short or fault or whatever you call
> it.  I have the following set-up:
>     The aux battery is fed by a big solid wire going directly to a canister
> type solenoid under the driver seat and then  (solenoid "out" terminal) to
> the aux. battery terminal.  That solenoid takes it's switching power from
> the ignition switch from a lead that is hot only when the vehicle ignition
> is on.  Starting the vehicle causes the solenoid to de-power when the
> starter is cranking, then switch back on .  I also have a second toggle
> switch in that solenoid 'control' circuit so that if my coach, or Aux batt.
> should be dead flat, I can send power only to the main vehicle battery, not
> both.
>
>   From the coach battery (under the driver seat) I have a big wire going to
> a fuse block in the under-sink cabinet.  That fuse block gives power to all
> my electrical systems other than the normal vehicle operating systems.
> (water pump, fridge, auxiliary interior lights, stereo, power outlets for
> 12v)
>   Each in-use terminal is fused.  No fuses are blowing.
>
>   So, how do I find out which circuit is 'leaking electrons' and causing
> that battery to drain?  I should be able to use this millimeter to trace
> where the power is escaping, right?  Right now, I am thinking it may be the
> stereo, which has a quite bright 'face' light that remains on (a small wire
> is always 'hot' to retain the settings and run the clock).  There is a
> second wire for the main power..I have both these wires connected to the
> same 20amp power terminal, always hot, powered from the coach battery.
> ..Last night, I removed that stereo fuse and re-connected the 2 amp trickle
> charger to the aux battery.  Right now, after removing the charger about 45
> mins ago, I have a reading of 12.8 v on the aux battery after 10hrs at 2
> amps.  I plan on re-testing in a few hours, and if I get 12.8v again, I
> probably found the circuit with the "leak" right?
>
>   It seems as if the stereo may be 'leaking juice'.  How do I find that for
> sure?  I have tried (now, don't laugh, I said I was an electrical dunce..)
> taking a reading from the lead > fuse block to the stereo...but it gives me
> 'battery voltage"...Should I put my tester on the stereo chassis and to
> ground to see how much is moving through, or what?
>   Also, there may be some operator error on the stereo, because I have no
> manual and have relied on the "infinite number of moneys, infinite
> typewriters--eventually you get the Declaration of Independence" method of
> re-learning how to make it work...pushing buttons till it does what I want,
> and then remembering what I pushed for the next time.  I have tried
> everything to get the light to go off on the dial/faceplate of the
> stereo..(A Sony MD/am/fm receiver) but it always stays lit up, unless you
> "release" that face using a button supplied, and put it in the glove
> box...An anti-theft feature, I suppose, that 'quick-release face"  It may be
> that leaving the face plate on draws too much current and it was designed to
> always be removed..or perhaps having the main stereo lead  connected to aa
> always "hot", unswitched lead won't work with this unit..I wired it that way
> so I could use the stereo off  the Aux batt. without having the ignition key
> on..Maybe I should put another toggle switch into that larger stereo lead
> wire, and leave only the small 'maintain-settings/clock' power lead
> unswitched?
>   Sorry for the length of this..
>  anybody wanna help a  fellow who knows just enough about electrons to get
> into trouble?
>
>   Don Hanson
>