While trying to trace the problem of why my Tach would not work, I found the problem in my coil connection. About 8 months ago I switched a coil from a series II into my series V paying close attention to the physical position of the connections from the series II(not looking at the + or -). I connected it up in the same way it was connected on the series II. I hadn't been thinking about the difference in + or - earth so I ended up installing it incorrectly on the series V with the connections set for a positive earth car.
What I don't understand is why the engine ran just fine with the terminations wrong. I've been driving it for about 8 months that way. I switched it back and the engine still works and also now the tach works. Does anyone know why the engine would work with the coil terminations reversed and have I done any damage to anything because of it? Do I need to reset timing or anything?
This is a pretty forgiving car if you can make a mistake like that and still run the car!