So, engine earth strap and battery earth to body cleaned. Also cleaned up alternator connection. Remeasured current drain with ignition off which was 1.5A on initial connection falling after a couple of secs to 27mA so this looks ok. Battery voltage engine not running 12.3v. Just after starting from cold 14.1v but gradually falling as engine got warmer to 13.73.
Voltage at back of alternator from cold 13.95v gradually falling as engine warmed up.
Switched on wipers, blower and headlights and battery voltage idling 13.2v and at back of alternator 13.8v.
Battery voltage @2000 rpm 13.56v (no change from idle- engine was warm by this time)
Alternator voltage at this time 13.88v. Alternator voltage @2000rpm with lights etc on, 13.77v.
Is it right for the voltage to drop off gradually as the engine warms up, indicating that the battery is charging? Do the voltages look right to people?
Grateful for any help
Thanks