voltage issues

me battery light has been on for a while now dimm at first but the faster u went the brighter it got..i was told its probably the diode?

the light was on but the battery guage was generally around halfway.and the voltage meters connected to the battery and 2nd battery on the split charge system when driving were reading around 14.4volts

tonight i fitted the alternator of me old td engine onto the 200 tdi..

battery lights now out but the volt meters are reading 11.9 or 12volts and the battery guage on the dash is on the lower orange section

any ideas why ?

what volts should i be getting and where should the battery guage needle be sitting?

you need 14.4 volts to charge the battery, what is the voltage of the batteries with the engine off?

i would have to check with the ignition on..went out again tonight and its still the same..could it be just unlucky to have a dodgy alternator again!!

ok...

healthy, charge battery, on its own, no engine, 12.5 up to about 13.1 volts.

with engine running, after a few mins to top up the charge used to start, about 14.4 at tickover, raising to approx 14.7 at fast tickover, no electrics, load up with fan, lights, etc, should drop but not to below 13.

check the wiring.

with the ignition ON engine OFF you should get 0v on the wee alternator wire and +12 on the big brown one, start the engine and these should both be +12. (well, about +14.4.) mind your fingers.

it was a dodgy alternator..got a remanufactured 65amp one bunged that on and all is hunky dory..just bad luck to have 2 dodgy alternators i spose