MG Car Repair: Continuous blown fuse 1970 MGB, oil pressure gauge, blown fuse

Question
Hi Howard
Just replaced theclutch and hydraulics im my B.Now am blowing fuse controlling directionals ,backup lights,temp and oil pressure gauge. I know what fuse is blowing but in the dark of how to trouble shoot for  obvious short. Discontinued the connectors for backup on the tranny  but still popping fuses.Any suggestions on how to find the source of the problem. Possible I pinched a wire while reinstalliong engine?

Thanks  Ron  Canton, Mass.


Answer
Hi Ron,
When you have several items failed and they all are powered by one fuse, you need to remove all of the wires on that one fuse from the fuse box (green wires) and connect up one at a time to ID each item. Since this happened when the engine and trans was R&R, the most likely was the backup lights. Label each green wire with tape and install each wire one at a time to see which is the shorted wire. If you have to drive the car a little for it to blow the fuse, then operate the car with just one wire connected at a time. (It would be advisable to leave the backup light wire till last.) Once you have isolated the short to one wire just look at the wiring diagram and trace that one wire to each point to locate the short.
Howard