My car has been stood about a year. Old battery was knackered so ive put a good second hand one on it. I need an MOT so have only ran the car on the
drive whilst doing the brakes. Ive noticed the charge light wont go out. Is this likely to be a knackered alternator? Just wondering what else i
should check before replacing it.
Ill be going for an MOT this weekend so ive got fingers crossed that the light is only on cos the car needs a good run out and time for battery to get
a good running charge. Im wondering wether the second hand battery is actually as good as i think it is???? It will be a bit embarrassing taking it
for an MOT to find it is flat and car wont restart. I might have to get some insurance on it and go for a little run out when its dark (quiet).
Car is 1999 audi A3 1.8 T Sport.
mine does this untill you rev it hard to activate the exciter coil.
normally its about 3k RPM untill it goes out. and stays out after that.
Chicken and egg situation.
1st check no wires are disconnected at the alternator or battery.
A fully charged battery should read 12.8v across the terminals.
Measure the voltage across the battery with the engine running, an alternator that is charging should produce at least 13.4 volts across the
battery with the engine at 1500+ rpm and the headlights switched off, repeat test with headlights on the voltage should not drop below 13.2 volts.
quote:
Originally posted by teegray19
mine does this untill you rev it hard to activate the exciter coil.
normally its about 3k RPM untill it goes out. and stays out after that.
check fuses on top of the battery
Fuses on top of battery checked - OK.
All wires connected.
Voltage when running (lights off) - less than 12V.
Looks like i need a new alternator. Strange how it was fine a year ago when last used. Never mind, not such a big job.
Thanks for your help again, much appreciated.
[Edited on 12/4/13 by DarrenW]