I have a Volvo KAD32 (170hp diesel, supercharged, turbo 4 cyl) that is 18
months old, performing like a train on a 26 ft Flightcraft flighbridge
cruiser.

I tried to start it today to find the starter motor spinning freely, with no
engine cranking.

I removed all electrical leads and cleaned them up in case of excess voltage
drop, to no avail.

I guess the problem is with the solenoid, not engaging the starter. Any
ideas on what might be the actual problem? There is a white plastic fuse
like fitting on the -ve lead to the solenoid - looks like some sort of fuse
arrangement - would this be likely? I tried taking the starter out, but I
found 2 nuts and removed them - must be another as it won't budge. Any
ideas on how it is removed for inspection?

Thanks