Evening all,

Was out in the car earlier tonight, short journey and the battery warning light came on.

Had the same problem the other week when the alternator belt snapped. Belt replaced and all ok again.

Been fine ever since until tonight. Went out another run just there, battery light still on. Alternator belt still intact.

Scanned the car with vcds, no codes showing up.

I think its still on the original battery, 178k on a early 2005.

Could this just be a knackered, tired battery ?

The car starts ok etc..

Edited 14 May, 201313 yr by swil00

probably a knackered battery. 8 years is a long time for a car battery nowadays

Id get the charge rate checked as the alternator could be on its way out at that mileage. Normally if the battery warning light comes on its due to the alternator not charging.

my god 8 years on the one battery! thats done well, mine only done 4 and has to get replaced, it didn;t throw the warning light it up, it just didn't hold its charge overnight, and had to get a jump off the guy next door. got it replaced and it was fine after that. was a 57 plate mk1 octavia 1.9 tdi PD

+1 for the alternator.

Battery doesn,t show a warning light when its knackered.I would say its the charging thats the problem.

Well today was an eventful one.

Started the car this morning, no battery light so off I went to work. 10 miles in and the battery light was back on.

Turned radio, climate etc off.

The battery struggled a bit through winter, so decided I was going to get a battery anyway. 10 miles from work and things weren't good with the old octy.

Decided to head for euro car parts, waited on them opening to get a battery. Must as I arrived, I lost all power including the power steering.

Battery changed and back on the road, but the battery light still comes on with no load on the engine.

Made it home ok tonight, so now it's booked on for diagnosis on Friday....

sounds like the alternator then. Have you checked the voltage with a multimeter?

+1 for the alternator.

Its the alternator.

If you're confident with this sort of thing and have the time, inspect/change the alternator's brushes & bearings. Both are wear items that can be knackered by 100+k miles. Clean the pulley in case a build-up of old belt material is causing slipping.

It was unlikely going to be the battery, more likely a connection got disturbed when replacing the drive belt.

The guzzi has a bosch alternator (same basic design as a car) and has given these symtoms in the past. Was usually a connection, or earth, but the stator, or more likely, field windings could go open circuit.

Could also be the alternator brushes, as skodacarman says. Some Bosch alternators have the brushholder combined with the rectifier/regulator. You can renew everything at once (should skoda ones use 'em. Replacement is not difficult, if you have the tools, parts and patience.

A quick open circuit check or stator and field windings and feel the bearings for play, before you spend anything.

Well, diagnosis done.

They reckon its the voltage regulator on the alternator that's had it.

Can't figure out where the 2.5 hrs labour to change it comes from right enough.

My phone we went within 15 mins of leaving the garage.

2.5 hours will be about right to remove the alternator,strip it down & fit a new regulator & re fit it to the car. This way will be alot cheaper than replacing it with a new alternator.

2.5 hrs is to remove the old alternator and fit a new one.......

Might have been better putting it into an auto electrician.

Edited 16 May, 201313 yr by swil00