Thanks - starting to make sense now. I have got a voltmeter - is there a test procedure?

Set meter to ohms or if it has a buzzer use that , carefully remove at least one end of the fuse from the fuse holder, but really take each one at a time and check is the best way , then put leads on the ends of the fuse, it should buzz or at least change resistance if you set the on Ohms  got it??