Hey all.

My battery light just came on, 200m from home at the end of a 400km+ drive. Talk about lucky.

What's the best sequence and process to determine what issue is? I do most of my own work on the car so I'm pretty mechanical, have a multimeter etc etc.

Just looking for the best approach to eliminate things in the best order, rather than charging down some path that might not fix the problem.

Notes to help diagnose:

Serpentine belt is tight and functioning.

Battery is nearly brand new.

Everything electrical looks to be connected properly and in good order.

The car recently had the leaky power steering issue (months ago) - steering fluid definitely leaked down into the alternator area before the leak was fixed.

Any help and advice much appreciated.

Multimeter on battery with engine off is around 12.5V

Repeat the test with the engine running - voltage remains roughly the same (~12.5V).

Multimeter on battery with engine off is around 12.5V

Repeat the test with the engine running - voltage remains roughly the same (~12.5V).

get a sparky to do a load/battery/alt test on car - tests battery & alt. had to have one done on one of my cars. fitted new battery but still had problems with no start. people that supplied batt did this test with no problems & sparky did it too. 2nd time sparky checked it out ... showed up battery fault. anyway ended up with a brand new battery & car was fine after that

[quote="Mad2"]get a sparky to do a load/battery/alt test on car

Cheers man. But the reason I'm researching here is so I DON'T need to get a sparky in. I usually fix everything myself on my cars, unless it's something that involved plugging in a diagnostic computer...

Thanks for the suggestion.

ok ... then checkout internal condition of the alt with a bright light. if it looks really crappy . . . replace it with a known working unit? did that with other half's BF [no problem with the light] .. did appear to be a change afterwards.

Alternator will have oil damage from leaking power steering change it .second hand will most likely have same problem. Check power supply is present at main connection to alternator.