test for Earth leak

[The Mighty Red]

can anyone tell me how I test my AU for a leak in the electrical system....My batt keeps going flat every 3 or 4 days, I fully recharge it and 3 or 4 days later its flat again.
I have a multimeter and a test light , my knowledge of multimeters is very limited but I have tested the batt when the car is running and its showing 14.3v which would tell me that the batt is charging when the engine is running...I put the m,ulti on the batt when it wouldnt start and it was showing 10.3V
the XR6 doesnt get driven very much anymore so if I did have a leakage problem earlier I probably didnt know about it because up until a a month or so ago it was a daily..

So how do I test the system for a leak?

[BillC]

How old is the battery ?

[5.0 ED]

Does it have any aftermarket stereo components? Amps are very common for pulling extra power.

What you would need to do is with everything off, disconnect the battey + put the leads in current/amp section of your multimetre, and set it to the high amps range normally 10amp, and put it inline with battery to car wires, red lead to battery + and black lead to cars wiring, whateva you do don't turn on car or have open doors or anything. And then post what your current reads.

Have you thought that you may have a faulty battery? When battery's get old they sometimes form a slight internal short, which makes the battery go flat by itself. You could find this by disconnecting the battery and leaving it set for days and then seeing what the voltage is or if it will still start the car.

[The Mighty Red]

batt is about 18 months old, no stereo amps,..ok I not really following because I am unsure of which setting I should be putting this dial on and the meter has two red (one has 10A max the other vmA etc) and one black socket....I put the dial to 10 the reading I am getting is 0.75

[BillC]

First thing I would do is get your battery tested. If that comes back OK then you need to start to get more technical. Just like 5.0 whiteaughia is saying. If you don't understand his description then you probably shouldn't be doing it. Take it to an autoelecrician. You could do a lot of damage if your not sure what your doing.

[The Mighty Red]

Auto Electricians charge $100 per hour, I would rather try and fix it myself thanks

I wonder if the OBD2 would throw out a fault code for a leak in the electrical system?...multimeters have half a million settings so it will take a bit of getting used to but I managed to test whether the batt is charging or not without blowing anything up.....

[dusty86]

get your test light and have one clip on the negative terminal and the other on the actual post then disconnect the negative and if your light lights up then you have current draw, then start disconnecting stuff (taking fuses out) till your test light goes out then you ahve founf the system whihc is drawing power, if you ahvea n aftermarket alarm it's possible this is drawing power

[The Mighty Red]

Ok cheers Dusty I'll give it a go tomorrow..

[5.0 ED]

On 10amp setting, with red post in 10amp spot, now if you have done that, and you got a 0.75amp reading, then it does sound a little high for a standbye current draw, i'll check mine tomorrow to see what mine draws to compare.

[speedzter]

Originally Posted by The Mighty Red

I put the multi on the batt when it wouldnt start and it was showing 10.3V

Was the 10.3v reading when cranking the starter or before/after trying to start ? As has been said, take it to a battery outlet and test it on a Carbon Pile load tester. Should be free !

[jjj]

Could be a defective diode pack inside the alternator, known to cause similar problems which you described.

[ronwest]

Originally Posted by jjj

Could be a defective diode pack inside the alternator

May well be.

My daughter's Commodore had similar symptoms to Reds but it wouldn't even keep a charge overnight.

I checked diodes with multimeter and sure enough were leaking a bit over 4 amps which if I remember my high school science is around 50 watts.

Googling for "test diode leakage" or something like that will show how to test.

[The Mighty Red]

Originally Posted by dusty86

get your test light and have one clip on the negative terminal and the other on the actual post then disconnect the negative and if your light lights up then you have current draw, then start disconnecting stuff (taking fuses out) till your test light goes out then you ahve founf the system whihc is drawing power, if you ahvea n aftermarket alarm it's possible this is drawing power

Ok dusty , I have tried your method and , the light is coming on , It is actually pulsing, dim to bright dim to bright.....So what know?? pull out fuses one at a time untill the light goes out and then ?...

[5.0 ED]

Things like the clock and alarms will cause the pulsations, just remove the fuses one by one until you find which fuse is the colpret, i'd start with the likes of the clock and radio, and then ecu, cause these are the main normal ones that do draw a standbye current.

[mik]

boot light staying on? glovebox light?

[mik]

any updates The Mighty Red?

[Stav]

The back boot light has a power down feature .After half hour odd the bem disconnects the power.Check the glove box/power windows/car radio /amplifier......If you have a battery backup siren alarm they also die drawing excessive power..

[The Mighty Red]

Originally Posted by mik

any updates The Mighty Red?

I havent had a chance to start pulling fuses yet, the battery is on charge and I will start taking fuses out over the weekend