A most difficult problem to diagnose. The engine is freshwater cooled with an electrical circulating pump for the freshwater side of the system. The pump and starter both run off a circuit that is discreet to all the domestic electric system with a diode taking current to the domestic and engine system.
Starting was weak with a low charge state on the engine battery. Charged up with external battery charger and seemed ok but still weak starting.
Got into port Wednesday and noticed coolant spill; seems overheating caused coolant to boil up and spill from header tank.
Result – The starter motor had gone bad and was continually drawing current; after a period the engine battery was sufficiently discharged to be unable to power the circulation pump. A hot diode also gave an indication that current flows were abnormal.
Striped old start motor and bought it to Andrej at Proelectro in Hellevoetsluis for bench test who confirmed multiple failure (it was hot to the touch in service so suspect winding insulation earthing). Andrej sourced a pattern starter, fitted this morning and brmmmmm.
