Trouble with the alternator, any ideas?

[VLC86]

Hey guys.

I don't actually own a VY, this is to help my uncle who has a completely stock VY commodore.

So a month or 2 ago he was driving around and the 'check alternator' light flashed on. The next day the car had a flat battery, so he called RACQ and they came out. He checked the battery and filled it up with water because it was dry. So the car then started and he drove it around until yesterday when the same thing has happened. He couldn't drive his car that day and isn't sure whether it will be the battery or the alternator.

any ideas? I'll talk to him soon to make sure what i said is all right.

thnks VLC

[Benboy]

Could be either. Consult an Auto Electrician.

[VLC86]

Yeah, he might have to take it to the shop. Just trying to save a bit of money if it can be checked easily

[ARATIC]

I guess the easiest way to see if the alternator is working properly is to put a multimeter over the battery while the car is running. If its anything different to 14 volts or so theres a problem with the alternator.

In all honesty though it sounds like the battery is stuffed

[wortus]

How old is the battery? I'd check the voltage with the engine running and see if the alternator is charging, shoudl be aroud 14 volts. You can also load test the battery put a volt mete ron it and crank the engine with the fuel pump fuse out and see if the voltage collapses. Alternator could just need new brushes and you can buy them and solder them in yourself.

[VLC86]

Yeah i was thinking it could be the brushes, they'd be easy to replace, just take out the regulator. Ill tell him to try the multimeter while the car is running.

If the voltage is going down while the car's running then the alternator is stuffed, if the voltage stays regular then the alternator is charging it alright. It might be the battery is just old, no idea how long he's had it.

[acarmody]

If the battery went too flat it may be permanently stuffed.

[VLC86]

well here a funny result to the whole situation...

car is now running fine, apparantly the car was left on a slope with 1/4 of a tank of fuel left in it. And because the fuel pump wasnt getting enough fuel thats why the car wasnt starting..

sounds odd to me, but the RACQ mechanic did all the tests including the alternator and battery and they all checked up fine. He checked the fuel pump fuse or something and that told him it wasnt getting enough fuel. Anyway car got a few litres of fuel in it and it started straight away. Can't explain why the alternator light kept coming on but we'll wait to see if it happens again

thanks for the help fellas