Hi folks.
A friend has a BMC 1.5 engine in his Liverpool boats 55 ft. Cruiser stern Narrowboat. There are two alternators;the
55amp one serving the starter battery behaves normally ie. the ignition light goes out immediately the engine starts and
the ammeter shows a charge. However, the alternator (90amp) for the auxiliary bank of 4 110amp batteries refuses to kick
in and start charging unless the engine is on maximum revs;this happens every time,not just on initial start-up.
Once charging commences all is well. We suspected a fault in the alternator itself,but replacement with a reconditioned
unit made no difference. We would be grateful for some advice from the electronics experts on the Forum! Incidentally,there
was a battery management system fitted but this became faulty and has been disconnected.