Battery Drainage
Moderator: martauto
- Brianmoooore
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Sorry, can't see a black arrow on your picture.
There should be:
The thick cable coming from the battery.
A thin wire following the battery cable back.
These are the two going to the left in your picture.
A thick black wire going across the engine and dissapearing downwards by the end of the fuel injkection rail, going to the starter motor and on to the altenator.
A thinner red wire (under sleeving), going into the engine loom.- The one that goes through the bulkhead under the power terminal.
Two red wires together which go across the top of the engine to the fusebox.
There should be:
The thick cable coming from the battery.
A thin wire following the battery cable back.
These are the two going to the left in your picture.
A thick black wire going across the engine and dissapearing downwards by the end of the fuel injkection rail, going to the starter motor and on to the altenator.
A thinner red wire (under sleeving), going into the engine loom.- The one that goes through the bulkhead under the power terminal.
Two red wires together which go across the top of the engine to the fusebox.
- Brianmoooore
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Can see the arrow now, but still can't say if its the one that goes to the engine loom or one of the pair that goes to the fusebox. You'll have to trace it along the top of the engine.
The black arrow is pointing to the wire that is carrying my battery drain.
I tried to follow the wire but it goes into a bit of sleeving and goes down behind the engine, so im guessing it could be my starter or alternator giving me my problem.
More than likely to be the starter since i already had the car in at a garage to get the alternator checked to which i was told that all was fine except for a set of brushes.
The car is going in this week for a service plus MOT work so all could be sorted soon i hope.
I tried to follow the wire but it goes into a bit of sleeving and goes down behind the engine, so im guessing it could be my starter or alternator giving me my problem.
More than likely to be the starter since i already had the car in at a garage to get the alternator checked to which i was told that all was fine except for a set of brushes.
The car is going in this week for a service plus MOT work so all could be sorted soon i hope.
I just sorted my battery drain by replacing the alternator. Should have been able to just replace the voltage regulator and brushes (combined unit), but the original alternator had already been replaced at some point....and was a cheapo value version.
- Brianmoooore
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MarkP - If the leakage current is going down the thick wire to the starter, then your problem is the regulator/brush pack on the altenator.
Either renew the pack or change the altenator.
Either renew the pack or change the altenator.
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Templ8e30
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The reason you are getting the -1 reading is because the meter is 'out of range' ie the current draw is higher than thte meter can read on that setting.
Try switching the meter to 500ma or whatever the highest range is. First thing I was taught about multimeters as an apprentice spark was to start at the largest range and work down till you get a good stable reading.
As already mentioned the diodes in the alternator go t!ts up and start to pass current draining the battery.
I had a problem with a Mk2 astra draining the battery and it was the rear heated screen relay stuck on, replaced the relay and the problem went away.
Cheers,
Iain T
Try switching the meter to 500ma or whatever the highest range is. First thing I was taught about multimeters as an apprentice spark was to start at the largest range and work down till you get a good stable reading.
As already mentioned the diodes in the alternator go t!ts up and start to pass current draining the battery.
I had a problem with a Mk2 astra draining the battery and it was the rear heated screen relay stuck on, replaced the relay and the problem went away.
Cheers,
Iain T
Turns out i have followed thr wrong wire from the power point, the wire causing my drain does indeed run to the fusebox. I pulled out each relay and the drain was still there so i started pulling fuses.
It is fuse number 21 and 27 causing drains! So what i thought was 1 probelm has now became 2!
Fuse 21 is the interior lights,clock,radio,torch etc
Fuse 27 is the central locking system (which isnt used cos i have a TOAD alarm),door lock heating, on board computer horn and Sound system.
Now i dont know where to start!

It is fuse number 21 and 27 causing drains! So what i thought was 1 probelm has now became 2!
Fuse 21 is the interior lights,clock,radio,torch etc
Fuse 27 is the central locking system (which isnt used cos i have a TOAD alarm),door lock heating, on board computer horn and Sound system.
Now i dont know where to start!
- Brianmoooore
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There should be some current flowing through both of these fuses when the car is parked.
You'll have to give us some figures for the leakage current.
You'll have to give us some figures for the leakage current.
- Brianmoooore
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Current drain should be in amps (or mA ), not volts.
Oh I don't know whether to laugh or cry.....
....just went to drive to get some milk and the bleedin car won't start again! Thought it had been sorted by replacing the alternator and it's worked fine since my last post. This is the first time its been stood for three days since it last happened though.
I'm really confused, can anyone offer any ideas?
To clarify, there is enough power in the battery to light up the dash lights and turn the blower but when I turn the key there is nothing, not even a whisper.
Dan
....just went to drive to get some milk and the bleedin car won't start again! Thought it had been sorted by replacing the alternator and it's worked fine since my last post. This is the first time its been stood for three days since it last happened though.
I'm really confused, can anyone offer any ideas?
To clarify, there is enough power in the battery to light up the dash lights and turn the blower but when I turn the key there is nothing, not even a whisper.
Dan
I've been having problems with current drain too. My battery was going dead overnight. I did a multimeter test and found that 0.34 amps was being drawn on Fuse 21 circuit. To verify, I left the fuse out overnight and the car was fine. The car was fitted with a clifford alarm. I never used the alarm since I didn't have a remote fob for it anyway. I have now completely removed the alarm unit from behind the glovebox and the current drain is gone. 
- Brianmoooore
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Danstable - does this happen EVERY time you leave the car for three days?
If it does, first confirm that your batter is good, either by changing it for a known good one, or chargeing it up and seeing how long it can run the sidelights for. (I know fully discharging an ordinary car battery is bad for it, but this one has been discharged a few times already).
The next time you leave it, switch off completely any alarm you have, and pull fuse 21. (Several of the prime suspects for this problem are on fuse 21).[/u]
If it does, first confirm that your batter is good, either by changing it for a known good one, or chargeing it up and seeing how long it can run the sidelights for. (I know fully discharging an ordinary car battery is bad for it, but this one has been discharged a few times already).
The next time you leave it, switch off completely any alarm you have, and pull fuse 21. (Several of the prime suspects for this problem are on fuse 21).[/u]
My alarm has been switched off since this last happened (I have switched it off at the siren unit with the key), this is the first time since it last died that I have left it for a three day stretch.
After the first time it happened the replacement battery would just about take me four miles over two runs before running out of enough power to start the car. Since the alternator was changed it has been fine.....until now. The battery was relatively new (actually, probably about 18 months old now) and is a decent make.
I will try to borrow the multimeter again and see what readings I get through fuse 21.
After the first time it happened the replacement battery would just about take me four miles over two runs before running out of enough power to start the car. Since the alternator was changed it has been fine.....until now. The battery was relatively new (actually, probably about 18 months old now) and is a decent make.
I will try to borrow the multimeter again and see what readings I get through fuse 21.
I've been told that if you replace a faulty alternator you should also replace the battery, is this correct? I assume that having completely discharged the battery twice, and had the alternator overcharging, my existing battery may be shot. Could this be the problem with my car?
Also, with the battery pretty much dead, is there any way that I can test it's health? i.e. test whether it will hold charge, before I charge it?
Also, with the battery pretty much dead, is there any way that I can test it's health? i.e. test whether it will hold charge, before I charge it?
- Brianmoooore
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Any tyre/battery place should be able to test your battery for you for free, but they'll expect to sell you a new one if it's faulty.
It will have to be charged first though.
It will have to be charged first though.



