Ignition...I think, any auto leccys here?

[Xentrix]

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)

[Xentrix]

Yeap, cheers for that, i'll try a 3rd relay. Be just my luck to replace a dud one with a very nearly dud one. LOL!

[thesals]

probably safer to stick with an old style mechanical relay, the cheap $10 napa electronic ones are no good, the more expensive $30+ electronics work a lil better, but electronic parts have a tendency to fail without giving any signs before they do

[Xentrix]

I think these are the mechanical type, a plastic cube style bout 1.5 inches each side and 4 big terminals on the base.

I've used them for all sorts of stuff and had no probs.

I'll go with the theory that I replaced a dud with a nearly dud.
I've been off work last 2 days and havn't felt like playing cars. But I will make the effort to change it again.

[The Al Show]

If it blows the third relay It could be the coil arcing to the terminal and backfeeding high voltage through the relay or maybe just a shorted coil that draws more than 70 amps.
AL