Can't help with Pertronix, never dealt with that or points ignition. My truck has Duraspark that works and when that gets replaced I'll be going to computer controlled ignition with Sniper EFI, so I got nothing to add or gain from this. That said sometime I really like looking at wire diagrams and something in that one caught my eye, so I'm going a bit off topic.

I understand most of what I see in that diagram, it's amazing simple compared to most newer vehicles, but two connectors have me scratching my head. Connector "E" in bottom center, I'm guessing that goes to the auxiliary tank sender on dual tank trucks? Connector "H", why even put it there? Was there some accessory or factory option that would have plugged in right there if the vehicle was equipped, and if so what? Aside from that there is only one purpose I can think of for that connector, and I'm not going to mention it on open forum in case someone actually uses it for that.

Sorry for thread jacking!

 

Thanks for both of the diagrams JEFFFAFA. Helps a lot.

Correct. But as you can see by the diagram, the visible wire at both ends of the Pink wire is the Red w/green wire. Should be able to see a bullet-type connector a few inches away from the switch where the resistor wire starts.
Sounds like your PO took it out and spliced in some regular wire. Usually it's easy enough anyway, since the resistor wire is designed to get hotter as it does more work, it's usually routed outside of the main harness and has a heat-resistant outer sleeve around it.

Back to your issue, without any kind of a resistor, it seems like your Ignitor I module would be very happy as long as it's paired up with the correct coil. Pertronix recommends their 1.5ohm coil for a V8 with 12v and their .6ohm coil for 6v (or likely with a resistor).
With the Ignitor II they recommend the .6ohm coil for all engines.

They don't like the voltage to go too low, but that simply makes them run erratically and should not actually burn out the module from having too low. Or too high voltage for that matter, up to a point.
I'm still trying to wrap my head around electrical theory with regard to ignitions (we've discussed different aspects in different threads recently) but when the voltage goes down, does the current passing through the Ignitor go up?

And speaking of voltage... What does yours read when the engine is running? Should be approx. 14.5v or so. Could yours be running high perhaps? Maybe extra voltage from the alternator is hurting the distributor modules. Have you measured it recently?

You don't happen to ever test the ignition by pulling a spark plug wire and holding it near the engine to see if spark jumps by any chance. Do you? I've found that errant sparks too close to the distributor can actually cause the Ignitor to die a quick and early death.
Just throwing that into the mix in case you were trying to track down an ignition issue with the old "pull the wire and see if it sparks" method.

Good luck.

Paul

 

Good question. The first thing I thought of was maybe an bed-mounted tank vs in-cab tank, but that would not have been a thing until later years I would not have thought. Were there '68's that had no in-cab tank? If so that might be the explanation.
Or it could be a mistake. Would not be the first time we've seen a mistake, even in factory diagrams. Not too often, but it happens.
Or, the shape of the connector and the color of the other wire makes me think of the neutral safety switch connector on some Fords. I wonder if that's what's going on there. Maybe just not showing all the possibilities. Automatics would have been available in '68, but I don't see any mention of an NSS in either diagram. Maybe an oversight?
Dunno...

But it's a cool thing to discuss somewhere. We might want to talk about it in another thread though, so we don't segué too far off the original subject.

Paul

 

 

Connector E was just used as a vehicle to connect wire 286 and 286A. And add in an extra wire to be used in the future.
Connector H was in fact hooked to a neutral safety switch for automatic trucks. M/T truck got the shown jumper. This should have been noted in the schematic.