Pertronix did not like magnet

In dialing in the new low-deck stroker I built, I went in to fine-tune what I had for centrifugal advance springs with the distributor in the engine. Having dropped a few E-clips and other small parts into Ford distributors over the decades, I thought I’d be ready and had one of those telescoping parts retrieval magnets handy on the small table I use for my tools.

I successfully swapped one of my two Mr.Gasket light 925D springs for a heavier but still light Ford spring from my spare Ford distributors. I reassembled everything, popped the Pertronix triggering sleeve, rotor, and cap on and went to fire it. Misfire, puzzled expression, then a few tests: intermittent or no timing light trigger signal on cylinders 1 and 3 (which are adjacent in the firing order, by the way).

More web research…found the recipe for how to confirm a bad Pertronix trigger signal with the car not running. The travel in centrifugal advance allows enough hand rotation of the distributor to watch for the voltage drop from 10-12v to zero on a voltmeter that indicates a proper trigger (analogous to points opening). Got a few “good” indications, then eureka! Two bad in a row that failed to show a trigger - I bet these were at the 1 and 3 cylinders.

A new Pertronix 1281 via next day air solved it. The new combination runs as it did before I opened up the distributor. So what happened? I can’t prove it was my only cause, but don’t set your Pertronix rotating sleeve or “Ignitor” module on the same table that has metal screwdrivers and a parts retrieval magnet. There’s a reason Pertronix gives you a plastic .030 feeler gauge to set the gap…



R.B. thanks for posting that. I often use a magnetic pickup tool and I’ve got Pertronix on one of my cars. That’s good info to know!!!

So…(he says rubbing his hands together in malicious intent)…it would be easy to sabotage someone’s ignition system by simply placing a large magnet near the dizzy…Hmmm…the possibilities… :mrgreen: :smiling_imp:

I suspect it’s not your fault nor did the magnet cause it. I have had several inoperative Pertronix units brand new right out of the box. I didn’t have any magnets nearby. They were simply bad brand new.

FYI all the bad ones were Pertronix II. Every time I get a Pertronix (original type) it is fine.

This was the original Pertronix points replacement, Royce. Like I said, I can’t prove my handling of it did it, but it was fine before I took it out to mess around.

A friend reports that he’s seen Pertronix I’s go bad in the car. Just as people used to carry a set of points or even condenser in the glove compartment, it might be good to have a spare next time I have $80 to burn.

I have heard the same thing on the originals as well. I keep the old points and condenser in my little cougar tool bag. JIC.

I just took a Pertronix 1 (It didn’t say anything but Pertronix on the box because it was the only kind they made back then) from my GT-E with 27 years of service and still working perfectly.

I installed another one in 1990 in my then daily driver 1965 Ranchero. That one is still working perfectly after 31 years in service. I sold the truck to a friend in 1995 but he still drives it daily for his lawn mowing service business.

Quite the endorsement, Royce!

These 2nd hand reports from car friends likely muddle all Pertronix stuff.

The older PerTronix units had issues burning out if the key was left ignition on, but the engine not running. This caught me & I put in the new one, had no problems since.