Thanks for all your replies. I will track down one of those battery testers Bill. Yes you are right, I quite enjoy most jobs on the boat....after 10 years there aren't many parts I haven't dismantled/ fixed..... but I hate electrics and batteries!
This may be a terminology thing US/UK, but where will I find the "ground solenoids"? I found the 55A ground fuse. That is what was causing the engine not to stop. ...... no idea about ground solenoids though.
SM 140 Sula