Right. Driving yesterday, warning lights started coming on, lost power, pulled up in a safe place and turned it off - tried to turn back on again (applying Windows logic ) and wouldn't fire. Called the RAC, diagnosed alt not charging, dead battery. Plugged my battery into his van for a half hour, to give it enough juice to get home.

Got a new alternator, swapped it over, fired it up - alt light took a few moments to go out, then went out - car idled happily for a couple of minutes, revved OK, all fine. Intending to take it for a long run to get the battery fully charged, packed my tools into the boot, and the car started to struggle. Tried blipping the throttle, no response.

So - does it need a bit of a charge off another battery or car (like the RAC man did) to get it going, then I can take it for a longer run to charge it fully - or is there something more sinister? Haven't got a voltmeter, but the RAC man's showed 12.5v rather than the 13.8ish it should have had when it was running - leading to the alt diagnosis.

Is it worth giving the battery terminals a wirebrush and a clean, perhaps to help?

Right. Driving yesterday, warning lights started coming on, lost power, pulled up in a safe place and turned it off - tried to turn back on again (applying Windows logic ) and wouldn't fire. Called the RAC, diagnosed alt not charging, dead battery. Plugged my battery into his van for a half hour, to give it enough juice to get home.

Got a new alternator, swapped it over, fired it up - alt light took a few moments to go out, then went out - car idled happily for a couple of minutes, revved OK, all fine. Intending to take it for a long run to get the battery fully charged, packed my tools into the boot, and the car started to struggle. Tried blipping the throttle, no response.

So - does it need a bit of a charge off another battery or car (like the RAC man did) to get it going, then I can take it for a longer run to charge it fully - or is there something more sinister? Haven't got a voltmeter, but the RAC man's showed 12.5v rather than the 13.8ish it should have had when it was running - leading to the alt diagnosis.

Is it worth giving the battery terminals a wirebrush and a clean, perhaps to help?

Perhaps try charging the battery with a proper self regulating battery charger for at least 12 hours.

Not sure if the TB may need to be realigned with VAG com etc if the battery has been disconnected.....although some people recon they self align over time, which would sort of make sense.

Bill.

`I had a similar problem, AA man also dignosed alternator failure, gave me a charge to get home and that was that. The actual failure was a fuse that had blown in the fuse holder on top of the battery. Must have gone with a bit of a bang because it actually melted the plastic holder around that area.

Worth a check if not done already...

Edited 14 May, 201016 yr by Andy Hames

Checked the fuses, nothing wrong there. Fitted a new battery (after 175,000 miles, gotta be worth doing anyway...), car started, no problem.

Only thing is, the auxiliary belt tensioner is past its best - and allowing the belt to slip sideways off it.

Is the wheel available separately to the rest of the tensioner? Is an uprated, non-nylon one available?