Driving home, radio cuts out, lights dim, finally engine dies. Cannot be restarted - starter motor just gives series of clicks doesn't engage. But hazards, horn, seat adjust, remote lock all work. Leave car at roadside overnight. Return in morning - car starts first flick. I drive it 5 miles to garage for check up. They say "Faulty alternator". I say "No way! How come car started and drove perfectly for 5 miles" Car runs but cuts out periodically as before. Any help in diagnosing this fault would be appreciated.

How did they check the alternator out?

If they put a DVM (multimeter) across the battery and the voltage went up to it's specified voltage (usually around 14-14.5 volts) with the engine running thenthe alternator should be OK. Of course you could have an intermittent fault but i'd check the connections to the battery/ alternator first as if these are loose it could also give the symptoms you're having.

Good luck and keep us informed

Adz

As above...plus how old is the battery?

I had a similar problem with a Granada, one cell faulty, would work for days then
all shut down to creep home mode.

thanks - will check this out and get back to you

Thanks, Adz,

They did meter the battery and got a reading of 11.5 - 12 volts. This could be just battery charge or if the battery was faulty i.e. down to say 9 volts then the alternator charge would make up the difference. So, I'm checking the battery out.
Could take a few days owing to bank holiday. Will keep you informed. Thanks again.
Pops.

Did they put the meter across the battery with engine running at say 1500rpm,
with the lights or something turned on?



This would tell you if the alternator was putting out 13 to 14 volts, as previuos writer says.

If it is, it's less likely to be an alternator fault.

Thanks - I will try this - Pops

If your battery is more than 3 years old, is most likely week or bad, it is recommended to avoid problems such as the aforementioned, is to replace the battery every 36 months. When you do the above the alternator/charging system should be tested to make sure no other components went in your foray. What is most likely happening, seems that most likely your battery ventured in what I would call, "the gray area." The battery is not really totally bad, nor totally good!

Your battery is not keeping enough charge during mortor/charging/operation, then in the morning it recuperates, as part of its reserve and starts the car. They can even be full of battery water. Sometimes when batteries are in this threshold, they even test good in meters, with the results you have. If you have another car, that you know the battery is great exchange it and run the experiment, you probably will see no problem starting and running. If you keep running your car as you are doing you will kill the alternator also, since the battery does not keep enough charge at times. it will make the alternator work harder in fact killing it softly. The click is characteristic of low charge, or in some instances the battery connections bad, and also the starter. I would go first testing the battery with a known good one, cleaning the contacts, and last testing the whole charging starting system. If all of this fails then you have some other bad corroded cable, or bad ground, but this is very remote possibility. Go for the obvious the battery and cleaning its terminals, making sure they are tight and free of corrosion.

C. PR

Battery has been checked again with engine running and returns 11.5 to 12 volts. Consensus of opinion at garages is that the alternator is at fault - that even with a faulty battery, it should reach 14 volts. BUT I'm inclined to agree with contributors here that I should try all the simpler options first. I haven't got another battery. If I buy and fit a new one, it seems to me that I can find out that way. Almost certainly needs a new one anyway. Comments appreciated.

Did you speed up the engine past idling speed?

Alternator does not always come in at slow idle

If you tried it about 2000rpm with the heated rear screen and lights on, it
should exceed 12 volts, if not it is suspect.

Thanks for this. However, I've now discovered that the situation is more serious. The power steering unit has leaked into the alternator damaging it. I will need to research lowest cost of replacing both. I believe there is a thread on here about this problem.
Thanks again to all who contributed.

Pops.