On one of my vans, the head unit is currently (no pun intended) wired
with the always hot and the switched wires using the same source.  If I
try to turn it off with the remote, the face stays powered up but if I
turn it off at the unit it doesn't.  Turning it off at the unit means I
can leave the van for weeks at a time without worry of it running down
the battery.  It's powered by the house battery, by the way.

FWIW, I put a switch aft so that when using the bed I can interrupt
power to the switched wire.  That way I don't have to get out of bed and
crawl forward to secure it at the head unit.  It's not a 3-way so I have
to have that switch on to use the head unit at all.

Mike

Billy Hirt wrote:
> Don,
> You should definitely make sure that the switched power line for the
> stereo is switched and not hooked up to 12v direct.  I have seen this
> many times including my own vehicle.  I simply put a toggle switch in
> to stop it from drawing down my battery.  These newer units tend to do
> that.  I have seen several times people just tying together the memory
> feed and the main power feed.  If having that fuse out does it then
> you more than likely have found your problem.
> Billy Hirt
>
> On Nov 4, 2007 8:39 PM, John Meeks <vanagon@gmail.com> wrote:
>> 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
>>>
>