Vauxhall Vectra B 1.9cdti 2007 - Intermittent starting - alternator? - merlinauto

My dad's neighbour has recently suffered starting problems with his Zafira (3.5 years old, out of warranty).

Occasionally gets slow starter motor operation. Once failed to start due to flat battery - 7V according to RAC technician. This was 30 minutes after a 5 mile journey. Started OK with jump leads; RAC said alternator was charging OK.

My dad did a quick test : 12.5V engine off, 13.6V engine running and no electrical load, 13.4V engine running with lights and heaters on.

I understand that these alternators are ECU controlled, similar to Ford Focus and Mondeo. There seems to be information around for the Fords but not much for Vauxhalls. Can anyone point me in the right direction for more information?

Finally is there any evidence of common failures on these cards i.e. alternator / wiring / ecu?

Thanks in advance

Vauxhall Vectra B 1.9cdti 2007 - Intermittent starting - alternator? - merlinauto

Ooops. I picked the wrong car from the drop-down menu.

Should be Zafira B! Sorry.

Vauxhall Vectra B 1.9cdti 2007 - Intermittent starting - alternator? - TeeCee

I had exactly the same problem with my Zafira "A" this time last year. I bought a new battery and it's been fine ever since. The one it came with (the car came with the receipt for same) lasted, by sheer coincidence, 3.5 years.

You don't say that it's been replaced since the RAC diagnosis and I'd suggest starting with the obvious. At least get someone to stick a rapid discharge meter across it as a check.

Vauxhall Vectra B 1.9cdti 2007 - Intermittent starting - alternator? - merlinauto

Forgot to mention that the RAC did a 'drop test' on the battery and said it was OK.

Further information on charging voltage, Retested this morning: engine off - 12.5V; engine idling - 13.2V; engine at 2000rpm - 14.6V.

Battery voltage dropped to about 11V when starter motor operated.

Vauxhall Vectra B 1.9cdti 2007 - Intermittent starting - alternator? - injection doc

often the most simple problem, at 3.5 years my first suspicion would be the battery.

Vauxhall Zafira B 1.9cdti 2007 - Intermittent starting - alternator? - merlinauto

Is it fairly common to see batteries start to fail at this age? The last five cars in my family have seen their original batteries last from 6 to 11 years.

The car is mainly used for short journeys, quite a number per day, so I guess this could contribute to premature battery failure (as well as alternator and starter motor).

I'll get my dad to keep his eye on it.

Thanks.

(PS Any idea where I can get more information on the alternator operation, just for my own interest?)