Discharging over the weekend

[Lawrence]

Hi guys, I have a consistent problem in that if I dont start the Patrol for a couple days, the battery seems to discharge somewhat and doesnt have enough juice to start the following monday. I have had it tested and the alternator seems to be charging and they cannot find any leak in the system. Is this normal? I didnt have this problem with the mk, which would start up even after a month of sitting down,

[chimpboy]

I wouldn't call that normal. Does it still do it if you disconnect one terminal? If it does then that points to the battery as the problem.

Otherwise you'll need to spend some time tracking down the culprit.

[Lawrence]

No, if I disconnect one terminal, then I can start it ok, even after a month.

[DamTriton]

Put an ammeter inline where you lifted the terminal off the battery. To discharge a battery over a weekend you would be looking at about 1-2 amps. If you don't have an ammeter, use a small globe (interior light, usually a handy "festoon" style). If it glows then you have a permanent discharge.

Next pull all the fuses (remembering what went where) and replace them one at a time, testing after each replacement, until you find what is drawing the current. Remove the fuses again as you go between each test.

Have you installed anything new recently? Could it be installed on the wrong side of the ignition switch?

[date]

Have you checked the condition of the terminal connections, or even the cable into the terminal itself? Maybe by undoing the terminal, you are disturbing the faulty joint and temporarily making good contact when you reconnect. After a while, it will go back to normal ie lousy joint. This is probably not the case, but it is worth checking.

As an aside, recently my friend and I did a quick trip up the Birdville track to the Cooper Creek. The next day, we went on Skytrek in the Flinders Ranges. This was in an 80 series L/c ( suspension was an optional extra which he forgot to order when he bought it!). Somewhere along the way, the battery must have received a shakeup, because it was very reluctant to start up in the mornings. The voltage seemed to be down although we didn't actually measure it. We were on the point of buying a new battery, but decided to hang out until we got home (we had a jump starter as a backup, but didn't have to use it). We get home and the battery is now fine - back to full charge etc. We can only assume that some oxide must have been shaken loose from a plate and was shorting out in one cell - dropping the thing back to 10 volts instead of 12. The piece has probably moved again and is no longer shorting out that cell. Friend is not complaining...

[Lawrence]

Put an ammeter inline where you lifted the terminal off the battery. To discharge a battery over a weekend you would be looking at about 1-2 amps. If you don't have an ammeter, use a small globe (interior light, usually a handy "festoon" style). If it glows then you have a permanent discharge.

Next pull all the fuses (remembering what went where) and replace them one at a time, testing after each replacement, until you find what is drawing the current. Remove the fuses again as you go between each test.

Have you installed anything new recently? Could it be installed on the wrong side of the ignition switch?

That way of testing it with a globe is definately a method worth trying. I will carry it back to the electrician an suggest some of these ideas as the last time he tested for a draw , he didnt find anything. Thanks for the ideas though guys and I will keep you updated.

[coat]

My dad has been having the same dramas with his 100 series cruiser. After the auto electrician having it for a couple off days and not finding anything, another place have tracked down the problem today as being the interier light. When it turns off after a couple off minutes the power draw keeps on hapening. A simple task of pulling out the fuse will fix it short term till he works out the real problem.

[BadMav]

I just replaced the alternator in mine as it was doing exactly the same thing (but when bench tested it jumped to over 15v and started smoking). You may think it is charging ok but it actually isn't and I believe the alternator in mine was also draining the battery when the engine was off (faulty diodes perhaps).

It hasn't drained the battery since being replaced.