help neede, batteries not charging (24V system)

hi there,

I need some help to sort out why my batteries are not charging. I don't know how to test if the alternator is giving voltage...

the series 3 is a ex-military version with the 24 volts system , alternator the AC5/24 model (31 amps at 27.5V) model if that helps.

Wiring is connected correctly , and earths are good.

I would be happy getting some advise.

Thank you

Hi, do you own a multimeter? If not, you'll need to get hold of one - you can get a cheap one for about £10.

Best initial test is, with the engine running, to check the voltage leaving the alternator, put the multimeter to V DC mode and put the red wire on the output of the alternator and the black wire on a very good earth point, it should read 27.5 volts i guess.

If that doesn't work, there will be a feed to the alternator which should be live (24v) when the ignition is turned on - this, in very basic terms, switches on the alternator, without this feed the alternator will not output any voltage, worth checking that.

Hello , yes a own a multimeter, thanks for your reply i will have a look at where this output is this afternoon
I suppose if it doesn't read anything i will have a faulty alternator

There's loads of info in this:

http://hmvf.co.uk/pdf/ALL CHARGED UP 4 ver4-1.pdf

Meant to say it might take a while to download, its 96 pages