Parasitic battery drain

[Siegfried]

Hi, a problem that can happen to any vehicle - something is draining the battery dead but you don't know what it is! Started on my T25 about 6 months ago and still haven't found the fault.
Disconnected satellite tracking, radio, 3 x new batteries, new ignition... Considering the alternator now... Anyone had/resolved this problem? Don't want to fit a switich to cut battery off.
Jump start is easy - from the leisure battery!
Cheers

[1664]

I had a similar problem on a Mini decades ago that turned out to be the alternator so I used to just unplug it when I wasn't using it. Easy on a Mini but a bit inconvenient on a rear engined vehicle with bedding etc over the hatch. You could try it a few times just to establish if that's the cause or not. If it's not that, something like this might help..

http://www.ebay.co.uk/itm/Automotive-St ... 5d25c1e62b" onclick="window.open(this.href);return false;

you might be able to source one cheaper elsewhere if you search around.

[Siegfried]

Hi 1664 - thanks very much - was looking for one in Halfords, but they had no such thing...will give it a try. Cheers

[AdrianC]

Have you been through the fusebox, one fuse at a time, with a multimeter to see which circuit's pulling current?

[Siegfried]

Hi
I have replaced the alternator, and still it is draining! Am going to fit an ammeter and voltmeter so I can see if there is a negative draw, then pull fuses to see which returns it to zero... I'll know which circuit it is on - then we can trace the wiring for that circuit. The multimeter wont be any good at this stage, as I need to know when there is a draw on the battery and the ammeter will show this - then I know I need to go and check.

Other thoughts about earth straps, starter bushes and so we go on... In for the long haul!

Will let you know when (not if) I discover the fault.

In the mean time off to Barcelona...

cheers

[matt_wannabe]

Iv just had a similar problem with mine if this helps. I found that the starter was really lazy when starting but just put this down to the engine conversion an I put up with it for a few months until I was intermittently not starting, just clicking so in my haste I replaced the starter, but unfortunately it was the same. Check battery an found ok just a bit flat which led me to testing the alternator output. It was barely over 12v so to cut a storey short. Found the braded engine earth on the gearbox mount was shot. Heavily corroded and generally just looked worse for wear. Anyway a new one was fitted and all is well now.

If you test your alternator output this will tell you have a similar fault. You should be getting about 14v I think. Good luck.

[Siegfried]

Hi
Whole new alternator fitted - no change. Went to Barcelona in Sept. No drain for 2 months! Then it randomly starts again. Have been advised it may be current arcing between two copper connections from the interior lights (which may have the usual blue/green deposits - bring connections closer). Have removed fuse... keep having to elimate things.

Any other areas/ideas I can attempt to eliminate?

Cheers

[1664]

Your best bet is using an ammeter otherwise it'll be a tedious process of elimination/experimentation.

[Siegfried]

Well, I have still have the problem!

Spotted fault with internal lighting wiring - recitified that - still draining.

Now spotted fault with zig unit - we can run mains from the three pin plug, with zig switches off! It's in the garage being checked. Good news - went straight through MoT!

Cheers

[Siegfried]

Hi
I think we have solved it! My assessment of the zig unit was wrong, but they did find a different fault. Loose wire preventing charging of leisure battery. I think the loose wire was causing the interior systems to draw on the main battery. The random drain fits with a loose wire scenario. I can only speculate on this, but since repair of the loose wire - no drain! Fingers crossed!
Cheers

[ghost123uk]

Loose wire preventing charging of leisure battery. I think the loose wire was causing the interior systems to draw on the main battery.

That can't happen (if your split charge system is working correctly, the main battery is isolated from the "leisure" equipment and a loose wire cannot alter that fact )

This issue would be very easy to trace using the amps section of your multimeter.

.

[Siegfried]

Hi
Don't spoil my illusion! Seriously - I understand what you are saying, however in the manual for the camper it makes reference that the mains battery can be used for leisure equipment too and it would be wise not do this for a lengthy period - obvious results! This is the only reason why I think there is a link....