Re: Cooling problem solved now what's wrong with my tach?
Do you have an ammeter or a battery monitor? Tachs on diesels are either run off the alternator or a pickup off the flywheel, usually a single wire sensor bolted into the bell housing/adapter. If the tach is off the alternator and it quits that's usually brushes (or a dropped wire) but if it's brushes then you won't be charging either.
Your loose wire is the first place to look.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)