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Model specific boards => Golf mk3 => Topic started by: Andy grim on 18 October 2015, 20:46
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Can anyone help put a new battery on the golf but it keeps
Going flat also my interior lights are flickering but when I rev it it stops could the alternator be at fault please help
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Yeah, probably the voltage regulator is gone (or its counterpart, maybe diodes). My money would be on reg though.
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Ok is it a easy job to replace the alternator it's a 1.8 se cheers
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5 minute job
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Really not for me lol
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Loosen both bolts, push alternator down and keep down, slide belt off.... allow alternator to come back up. Take both bolts out, off it comes. Fitting new one is reversal of above. 5 minutes easy.
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Ok will give it a go when the ignition is on the lights don't flickerer but the minute the car is running they flicker but when I rev it it stops thanks for your advice mate appreciate it :smiley:
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Oh btw... I only mentioned mechanical connection. There is a connector to regulator that needs to be pulled off and one cable to battery also needs undoing (very good idea to disconnect battery first!!).
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Ok is the regulator and the alternator one unit
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Yep, regulator is a part of alternator, it can be replaced rather than whole alternator but you need to have an eye to check alternator itself has not been damaged by worn carbon brushes.
I put a guide together on how to change them, it's in German but pictures should be enough.
http://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=716521
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Thanks but seen a bosch one on ebay so will probably get that thanks for all your advice :smiley:
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I tested the alternator today and with things on I got a reading of about 12.7 to 13 volts is that good was going up and down wasn't really steady
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I assume this was with engine running but nothing else on (lights, rear window heating etc)?
If all these things are off you should be getting about 14V. 12.7V to 13V and fluctuating means something around alternator is faulty (unless your battery is completely cooked - but then you'd have massive issues starting it up).
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No that is with everything on with the lights flickering could it be a bad earth?
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Where did you measure the voltage? If it was anywhere other than the battery terminals (like the cigarette lighter socket) then you should measure again. Internal voltages seem to be more regulated than the charging voltage. Or perhaps there is a voltage drop on the supplies to car internal power.
I never saw more than 13.4V on my Mk3 at the battery terminals but the battery never got flat in over 10,000 miles.
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No mate directly to the battery
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I used to measure away from battery as it is a massive sink hole for electricity....
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I am going to do the alternator because it sounds easy to do but I think maybe the lights flickering is a each somewhere that's not too good where's a good place to start earth wise
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if your engine fired up easily when the new battery was fitted then it is unlikely a problem with the main earth wire. not sure if the battery to bodywork wire being faulty would cause the flickering lights though? try measuring the charging volts directly of the alternator (thick wire from battery). if the reading goes up to 13.5-14.5 then the wire is faulty somewhere. if reading is the same then the alternator is probably goosed.
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So the alternator could cause the flickering lights have any one else had the same issue also I am keeping a eye on the battery drain two days ago it was on 12.37 v have not started it in two days checked it today and it's on 12.18v is the about right or two much drain cheers also have a 063 battery is it two small looks tiny for a 1.8 petrol thanks
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63Ah battery? More than enough for the 1.8
Yep, lights flickering is a fault mode for alternator (output voltage unstable). Faulty ground connection would give you other issues as well. Your fault is located in the alternator one way or another.
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Ok cheers also is the battery drain about right or is that too high
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Voltage alone only tells half the story. Would depend on whether the battery is dropping on it's own or due to car drawing power.
You would need to measure the actual current when the car is locked (and the bonnet switch is bridged) without interrupting the path (connect up multimeter before taking terminals off the battery).
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Ok bit of a update diffently have a battery draw somewhere haven't started it for three days and the battery was only showing 12v so today didn't start the battery is only two weeks old so can't be that getting a multi metre tomorrow so will check it's really annoying me now
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Does anyone think it could be a earth strap that's causing the battery drain
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No, it won't be that.
Check how much it really draws with bonnet switch bridged and car locked without interrupting the circuit.
Might just be radio that has both 12V lines connected to terminal 30.
I still think you have a daft alternator.
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Have disconnected the earth from the alternator and still
Draining the battery
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How have you disconnected 'earth' from the alternator exactly? ???
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There is that black lead on the alternator which has a washer on the end that connects back on to the alternator body is that not the ground for the alternator?
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Nope, that is the positive.... there is no ground wire to the alternator - it grounds through the engine metal work.
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Ok so I have still disconnected the alternator so can't be that but what I have noticed is last night I disconnected the battery and took a reading of 12.47 and this morning took a reading of 12.43 should it go down this much not even connected to anything thanks for your help on this mate
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Yes, it will always loose a little charge. Idle voltage is only one aspect of battery charge.
Without measuring the current it is difficult to tell why you are loosing some charge when the battery is connected up. Voltage fluctuations with engine running is due to alternator.
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No the battery was removed from the car a it lost that charge in 12 hours
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Yes I understand that, but you only lost 40mV when it was disconnected which is absolutely normal.
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Oh ok I see so by discounting the positive lead on the alternator it could still be taking juice off the battery?
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Not the alternator but the car still draws a small amount of current.
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Well euro car parts swaped the battery over but I think your right about the alternator so that's the next job