charging fault

[bagpuss 996r]

New battery recon alt, when all elec on only getting 12.1 on battery
when i asked for alt to be repaired told him it needed to be 100a
how can u tell if it is, surely if low voltage at battery it means
low current out of alt. When battery is charged on charger it had
13.8 on battery started fine but then had 12.5 when running on alt
please help if it wont start its just a lump of metal and cannot
trust it.and no its not the fuse.

>> Edited by bagpuss 996r on Monday 5th December 08:34

[mongoose]

Sounds like the alternator is doing little or nothing.A new/re-con alternator should show 14.5/14.6v once the exciter has kicked in(ie revving it a little).

[bagpuss 996r]

Thanks just phoned them will take it on wed is that on the battery
voltage it used to be 14.5 with or without load.

[mongoose]

bagpuss 996r said:

Thanks just phoned them will take it on wed is that on the battery voltage it used to be 14.5 with or without load.

The voltage usually is this high,even at tickover,its just that you can sometimes have an exciter that'll make full voltage only kick in from around 1500 rpm or so(variable figure this).Technically this is often considered acceptable if they work like this.Mine gives full volts at tickover,but i didn't want to assume that yours would,when it could still have been working ok,iyswim.