MG Car Repair: MGB Fuse line, blown fuse, fuse box

Question
I have a 1980 MGB and all electrical operations serviced by the the number 5 fuse line (turn signals, break lights, etc)have stopped working. It is not a blown fuse - there is no current running to the fuse box on that line. How do I go about checking the location of the line failure?

Answer
Hi Andrew,
The power for that fuse should be from the ignition switch. (it may also have a ignition relay) Don't just test the fuse, test the ends of the wires as the Lucas fuse box can have bad connections to the fuse box itself. You need a wiring diagram for the car to try to test circuits. If you don't have a diagram you can go to my web site and copy it. http://mg-tri-jag.net/78-80MGB1x1.jpg for the diagram and change the 78-801x1.jpg to 78-8021x1.jpg for the index for the diagram.
Howard