Random battery discharge problem!

Hello.

I have a problem which has plagues me for years. My van can be sitting unstarted for an unknown period of time and still hold a good battery charge, then it just sort of drains.
It isn't the battery, unless there have been 4 bad batteries in the row. And 'normal' parasitic drain seems to sit at about 60mA from the stereo.

For example it could be sitting for a week. I could wander out and check the battery by using the vent fan, headlights etc and they all can be at full power. but a day or two after that barely enough charge to even operate the headlight relay.

I ran it last week, just fine. today, not even enough charge to run the clock on the stereo.

It doesn't seem to be an even discharge. It almost feels like something kicks in and drains the battery once it reaches a certain point.

What part of the system is usually live during rest normally?

Incidentally, It had this problem as long as I can remember. Even back before it had this stereo.

I'd really, really like to hear any ideas on this.

i had a similer problem that nearly drove me to total mental breakdown whitch now explains a lot,
it turned out to be a relay when i turned the lights or anything it started the relay and when i turned all off the relay didn't shut off, so the next time you do ya thing after an hour go back and put your gadget on and check for drain

tristan.. haha man i saw this post and thought 'f#ckin what still havin problems' haha... it has been a while..
for your van.. its been a little while since i played electrician so its a bit foggy but here is some suggestions...
a) your ignition barrel is wired wrong/shorting out (inside switch or wires on the back..). when you turn your key to 'accessories' its supposed to enable that circuit.. perhaps your bus is wired wrong so its constantly live? you could test this easily enough.. test light on wires should bring light to only one wire, the positive from battery.
b) faulty relay (for whatever accessories would work with ignition off) as stated by greedy53
c) worn/exposed wiring in loom or fusebox... totally feasible for such a timeless beast.

simple solution. disconnect the neg battery terminal every time you leave it for a period. better solution, buy isolation switch for $10 and fit it at battery terminal. turn the red key and whammo- disconnected. better still, figure it out! ha!

by the way, you have checked that the alternator is charging the battery at a decent voltage and amperage? just check all bases..

good luck man

Sorry about taking so long to reply. Had some extra work recently. Well it wasn't the work exactly but just the resultant apathy if you know what I mean.

I'll just address this probably poorly in points.

*Light relay. That's actually a really good idea. I'll check how I wired up the driving light relay. I'm hoping I wasn't stupid enough to source the switching current from something always live.
There was also a auxiliary battery relay I put in. I disconnected it out of suspicion. No change.

The trouble with checking if something is causing uneven drain is I'd probably need to have the ammeter/multimeter connected during the whole testing duration. Which means I'd have to patch one in, in series and make sure it has a good battery (or get an analog) to last the duration needed to catch the unexplained drain increase. Fitting a permanent ammeter wouldn't be the the answer as it is possible the drain is coming from the starting circuit.

Is it possible the regulator is incorrectly wired up? Ie when voltage drops below threshold ...something happens? Probably a stupid idea, but I'm a bit stumped. I've never figured this one out.

There is no accessory option. Just Off, On and Start.

Where on earth have you seen the isolation switches for $10? That was my conclusion too. If I can't fix it, avoid it.

I'd totally believe insulation breakdown too. Especially during the wet. However wet is virtually nonexistent here and the van is kept in the carport.

Wow
thats a hard one...
a dual action relay could be connected up incorrectly
so its connected and is actually on all the time
that is the relay is using current all the time
so when its turned off
the lights come on or whatever...

so, the relay is actually drawing current all the time...
until the power is so low it goes off and actually turns something on....

Just one thing I thought of...
or it could be simply a loose wire...

I don't like amp meters because they have to be in series...
Use a volt meter and it May tell you when something is using power...

it could also be a fuse that is a bad connection...
and when it actually connects... randomly
it turns something on....

those Main battery Isolation switches are about $10 [from memory]
at auto one....
as I thought at the time...
to steal a car that uses one of those for security reasons

the thief can buy a key [and switch] for $10....

then go stealing cars protected by one of those....

Connect the memory from Your radio and clock direct to the battery...
if you still have the problem..
use an isolation switch which won't have any effect on Your radio clock...

cheers

Lee


http://community.webshots.com/user/vw68autobug

Could be the key switch as noted above....

the points in those would be very burnt after all these years...

I reckon greedy got it right, it'll be one of the myriad of relays. Swap them one at a time until it stops.

It has been sitting since I made the last post and it hasn't noticeably discharged. I even had the stereo on for a while and it still cranked perfectly. I just don't understand it. Oh well.

I have been messing around in the engine bay the last couple of days so if the problem is in there I probably aggravated it again.

I won't go into the problem in there right now. I made things worse, and won't be happy until I figure out what actually happened.

Disconnect Your battery
disconnect the CD player and clock..

then place a 12v lamp across the terminal you just disconnected so any power has to go thru the bulb...

if the bulb glows at all...

pull Your fuses out one at a time
and when the bulb goes out
You will know which fuse is causing the problem
or i should say whatever is connected to that fuse
is causing the problem...

Best of luck...

Lee

It'll have to wait a little before I can really do that. I'm a bit nervous about touching the electrical system right now. Once I put everything back in place after doing some engine tinkering I should be fine to. Probably today later on or tomorrow, depending on what time allows