Alternator Ignition issues.

Ok I just fired up the Willys and it was running for a while in the garage and then I was looking at the voltmeter and it went up to 18V where usually it is sitting at 13-14.I was not quick enough to shut it down and it blew the main fuse but it also looks like it took out the Hyfire 6 ignition as when I changed the fuse it has power into the box but no sign of life.Questions are can you send these boxes back to Mallory and would the only place for the spike to come from be the alternator.Is there a diode or voltage regulator that would be worth installing before the ignition module.Thanks

Yes you can send the box back to mallory. I would say that the reg. in the alternator went south.

The only time I ever seen 18 volts out of an alternator was one that shorted out the field winding. Then it put out more than that.

Yeh I am thinking the regulator went out,this alternator is a one wire and only three years old so now I am thinking how I can avoid this from happening again.Thanks

I hit 18 volts also when the plastic fan on a stock alt, (china carp) disintegrated and the thing heated up. I would think if you sent the box back to Mallory they will fix it.

Not real familiar with one wire alternators, but if its not the alt, you may need a volt regulator wired into the system. I had the same problem but with a 3 wire alt and put in a new volt regulator and that fixed it.

Thanks for the replys,am heading to Summit today and I found that Painless wiring sells a surge protector that goes across the battery and maxs at 14.5v so am going to give that a try as well as a new alternator.

I've used those surge protectors from Painless and they work good as i had a reg go and it did no damage at all.

Thats good to hear roadster32,just bought one but they have to ship it as wasn't in stock.They also swapped out my mallory 685 as it wasn't a year old so am happy with that.