How to troubleshoot a slow battery drain?

[chilidavid]

When my Daily Driver sits during repairs - the latest being a brake system overhaul - my relatively new (and expensive off-road) battery shows signs of power drainage, so much so that my Series 2a hesitated to turn over just after a week or so of sitting. In the meantime, my remidy is to disconnect the ground wire whenever I need to work on the truck. Is there a way to find out what exactly is drawing a charge? I don't have an electric clock. And my guages/lights, etc. are activated by my ignition switch. And my voltmeter shows a "normal" charge when driving, around 14+ volts. Any suggestions?

[Dietersrover]

This sounds silly, But.. Have you tried a different battery?

[busboy]

Often the glove box light remaining on can cause this..... OH wait there's no glove box, sorry couldn't resist. :D Do you have a radio/stereo these take some voltage to keep things going but not enough to drain the battery in a couple of days. As suggested a new battery might be needed. Newer vehicles have an IOD fuse (ignition off draw) that the dealers pull when the vehicles are sitting on the lot, this kills power to interior lights, radio, clock, those kinds of things, but the Landrover is so simple.

[ignotus]

I think you should pull the + battery terminal instead. Especially if +ground. To find the drain IIRC you have to pull the fuses and see when the draw is eliminated. If you still have the 2 fuse fusebox you might get a spark when the fuse is reconnected. Then you can figure out which circuit it is in. Just thinking outloud, I bet a test lamp with the fuses out will light up if there is a draw in the fused system. Remember there is a slew of wires(brown) that are unfused. Go HERE for some excellent wiring diagrams. You don't say if you have petrol or diesel but they are there. Is the voltmeter keyed power?

gene

another quick thought,, sometimes if an interior lamp is left on.......

[CKubinec]

Ignotus is on the right track but there is a better way to see when you actually have the draw. You will need a volt ohms meter that also has an amp position. My meter goes up to 10 amps which would be plenty for a slow draw. Turn off all switches and accessaries. Disconnect the positive battery terminal and hook the meter leads between the unhooked battery cable and the unhooked battery post. The meter should read out the amount of the draw. If the meter reads less than zero the leads are backwards. Now disconnect the fuses one by one until the meter reads zero or close to it. Now use the wiring diagram to follow that circuit as Ignotus said until you find the fault. You can also check unfused circuits but starting at the starter solinoid and unhooking wires until you follow the shorted circuit to the fault. It can be a tedious task if the short is well hidden or a long ways down the circuit.