I got a problem,

I got a 351C in a 79 Oz Falcon, it has electronic ignition and a factory Bosche coil.
It also has relay that puts battery voltage directly to the coil rather than go round the loom. However after 2 years, the relay crapped out. I fitted another one (70A this time) and off I went....for about 3 miles and it died again.

Being a tape and cable tie kinda guy, I just put a wire from the battery to the coil and drove home.

Anyone have any thoughts on what could be the issue?

I may just fit a switch in the dash so I can use it, but its bugging me.

Other than that the car runs great, (needs another 100hp as usual)