Back again - alternator switch coming on intermittingly

[DIYnumptyclown]

Just forked out £200 to repair my window regulator (thanks to those who gave their advice), now the alternator light keeps coming on. Referred to my car manual which says go to a garage.

Make VW Polo, 16v 52 reg

Bit of background, had problems with the battery running down in the summer - as a consequence changed the battery and the starting motor. Seemed to be working fine until the alternator light came on this week.

Slowly but surely getting fed up and poor!

Grateful for any advice from those in the know!

 

[Burnerman]

I reckon your alternator is heading for the great rotor in the sky, but if you want to test it:
Set a voltmeter to around 20v DC and start the engine.....the reading should go to around 14.4v, and not decrease much when the lamps or heated rear window are turned on.
If it can't manage that, then I'm afraid its goosed, so go for a reconditioned one if you want to save some cash over a new one, or a breakers yard offering if you feel lucky!
John

 

[DIYnumptyclown]

Thanks John for your prompt response.

How long should an alternator last for - approx and what should I look out for if I buy a re-conditioned one; would they carry a guarantee like a new one?

Thanks again.

 

[Burnerman]

You'll get a 12 month warranty from a reconditioned one, and the same from a genuine new article.....
If the replacement one is genuinely recon - i.e from Eurocarparts, GSF et al then I'd buy there with confidence, and have done several times.
One minor point - alternators are exchange units so more than likely you need to bring the old one in (which is great for matching up on the spot), but its usual for you to remove the pulley.
These suppliers won't check the alternator output for you though, but many other motor factors will - if you don't have a volt meter. Obviously it has to be still on the car for this.
John