alternator/charge info

[zookfest]

over the last week the ute has been turning over slower and slower until today whan it has no life in the batterys at all.now the batterys are brand new big buggers 2 months ago and had no probs.
so today i took the brushes out of the alternator and they still have a good 12mm

what do i check from here
its 24v system

[gimmemud]

Is your alternator charging at all? I had a problem with my alternator where it needed a permanent 12v to it and the wire had broken so it didn't know to charge.

[zookfest]

im not sure im guessing il need a multi metre,then how do i do it

[gimmemud]

With mine there was a plug on the back of the alt Which had two wires going to it. one was for the charge light on the dash and one went to the battery, if you can get a multimeter check that there is voltage to one of them. Guessing you've checked all the terminals are tight and the lead between batteries is sweet?

[sig]

with the motor running at a fast idle you should get approx 27-8 volts across the two batteries .if below 24 then its not charging

[rangimotors]

put it back together and ill bring my meter over

[zookfest]

ok last night i took the batts out and over to a mates who has a really flash battery charger and it turns out that 1 of the batts was stone cold dead and it was the one i was running all my 12v electrics off,sub,compressor,stereo amp etc so thats looking like the fault at this stage,it explains the slower starting power having robbed one batt alot more than the other

[Henry]

Hi

Are you running a electronic thing (can't remember the name) to equalize the charge if you are running things off 1 battery?

you will keep stuffing 1 battery if you are not and not using a voltage converter.

you either need to run a 24 to 12 volt converter, ( I have about 3 doing different things) or see a auto electrician to install the thing I was talking about earlier.

[Dodgysam]

I had this exact same problem last week. Battery was 1 month old but dead as a door knob.

Turned out it was the rectifier inside the alternator...$500.

Spoke to a mate last weekend and he works with electrics and told me a rectifier is a $2 part if you know where to get it from.