I haven't run my car for a couple of weeks whilst I've been playing/fighting with my exhaust

I went to start the car last night, but got the dreaded 'click click click'

I've charged the battery overnight and the car started, but the voltage was just under 12

I've just taken the car out for about 10 minutes, the voltmeter was hovering around 11-11.5

I ran the Durametric and got '9133 Term. 61 Low With Engine Running'

I was able to stop and start the car a couple of times, but now it's completely dead again

The car was fitted with a new battery 14 months ago, which is rated at 780 amps & 78 amp/hours (Bosch SilverTop)

Is there a way to determine whether my battery or alternator are toast?
Or is there anything else to rule out first?

 

I've had the car on charge since my last post (1 hour)

It started up again no problem, but the voltage is still around 12

I'll report back again shortly

 

Ok, two hours on.....

In car volt gauge shows around 12.5
Car starts and drops down to 12 volts

When the car is running the 'Battery/Generator Warning' light comes on


Battery charger is telling me the battery is fully charged

 

Sounds like a charging problem. Alternator/regulator. If you charged the battery and it's bad, volatge should still be around 14 running, showing the charging voltage. If battery was toast, your car would not restart at all when shut off.

 

It sounds like you now have 2 problems. Your battery is toast - it should read 13.7 after charging. ... And your alternator/voltage regulator is toast - the warning light is telling you about that one. Replace the alternator first, but if your battery still reads less than 13.5 after a couple of days on a decent charger, you will need a new one of those too.

 

Thanks mate

I'll leave the battery on charge for a day or two and see what happens (although the charger is already giving me the green light)

As far as the alternator, I've heard it's usually just the voltage regulator that's knackered
What do you think about replacing the regulator as opposed to the complete alternator?

 

It could be the voltage regulator... When I did mine I didn't want to live with the down time. It takes a couple of hours to get the alternator out and back in. If you have a local rebuild shop close by, just give them the alternator and let them test each part separately. For all the trouble and screwing around, I just ordered the alternator on-line and replaced the whole thing so I wouldn't have to do it twice. Your call...

 

Quick update

Durametric shows.....
'Power Supply' flicking from 13.07 & 13.0
'Supply Voltage' from 13.02 & 13.1

Let's see what happens in the morning

 

Update:
Charger shows battery as fully charged
Car starts fine
Generator warning light comes on
Volts are just under 12

 

Excellent - you are back to only one problem - if you act fast. You can get a Bosh alternator for under $300 if you stay away from the dealer. It takes an hour or two to replace it if you chat and drink eggnog while you work.

 

Sweet!
New alternator it is then

 

OK, I had to take my car for it's annual testing this week

The car needed front tyres, which they didn't have in stock, so the car has been off the road for this week

Since it was already off the road I've decided to try a new voltage regulator instead of a complete alternator

BUT, before I replace the regulator is there anything I can do in order to single that out as the faulty part?

I really don't want to be doing this twice

Thanks

 

I'm not familiar with the P charging system but in general the alternator puts out AC voltage, the higher the rpm, the more voltage. It may peak at over 50 volts AC. The voltage must be changed to DC that the car runs on which is done with a series of diodes, the DC must be trimmed to a max of around 14 volts which is done using other electronic components.

Sometimes the rectifier and regulator are combined within the alternator. Sometimes the rectifier is but not the regulator. Find this out first, what type you are dealing with. If it's all combined in one unit you can test each diode and replace bad ones very cheaply yourself. Current in diodes only flow one direction, if it flows both, it's bad.

This may help you get an idea and either encourage you or make you run away.

 

Thanks Nick

I have no understanding of electrical components, but things like this always encouorage me to learn

 

Regulator has now been replaced
I haven't started the car yet as the N75 valve is broken and needs replacing

The battery is fully charged according to my charger
With the charger attached my durametric shows

Supply Voltage 13.02v
Power Supply 13.00v

With the charger disconnected it shows

Supply Voltage 12.56v
Power Supply 12.54v

Does that look ok?
I've heard people mention 13-14 volts before
Any when I had it connected to the Audi to jump start it I remember the reading being 14 volts too