My van is eating batteries nom nom

[berty1702]

G'day

Sooo just wondering why my vans started to go through batteries like a fat kid eating cake?
Brand new batteries are lasting about a week before theyre completely flat and dont seem to charge up, (though i may have a dodgy charger)...
But still... should last longer than that?
Could it be my alternator?
Dead short somewhere? the wiring looks like a blind leper (missing a few fingers) tried his hand at electronics in the past....
leisure battery interfering with it in some way? broken split charge relay?
anyway im stumped, so any advice or guidance will be greatly appreciated!!!
My grandads gettin arsey about it being stuck on his drive! hahaha!

Big thanks
Rob

[kevtherev]

So have you tested the output from the alternator?
Have you tested the charge to the leisure?

without this information we can only speculate

[berty1702]

This may be a silly question but how do i test if the alternator is working or not?
Theres no power going to leisure battery when the engines off or running...
i put a bulb between negative on the battery and the body and it lit without the ignition on.... i take it thats not meant to happen? so took all the fuses out one by one but the bulb stayed on... it only switched off when i removed the 50a blade fuse in the box at the back of the engine... what does this mean? (if anything)...
By the way its a 1.9tdi...

cheers

[kevtherev]

This may be a silly question but how do i test if the alternator is working or not?

I can answer this one, set the multimeter to read DC volts put the red probe (+ve) on the large stud at the rear of the Alternator (the one with the thickest wire usually red) and the black probe on a good earth.
with the engine running it should indicate over 14 volts.
if it shows the same as the battery does, then ...either the regulator has had it or the diode plate has gone.

Does the red ignition light come on and stay on when you start the engine?

[BOXY]

i put a bulb between negative on the battery and the body and it lit without the ignition on

The van has got a negative earth system so connecting the earth side of the battery to the chassis definately shouldn't light a bulb! Are you sure you connected to the negative side of the battery? Having the ignition switched on won't make any difference if you're connecting straight to the battery.

Dead short somewhere?

A dead short will normally be easy to spot by the sparks, smell of burning and flames.