1950 Chevy 3100 No Spark

[ewhitaker0020]

Hello, I'm trying to help my father-in-law get his truck running again. It has sat for about a year and now we can't get it to start.

The engine turns over fine, the battery is fully charged and as far as we can tell it's getting fuel. The problem is that it isn't getting any spark to any of the spark plugs. I took a wire off one of the spark plugs and stuck it to the engine block while he cranked the engine and there was no spark at all. I did this to all of the spark plug wires and got the same result.

So we assumed the coil was bad and got a replacement. A big thing to know about this truck is that it originally had a 6 volt generator system, but now has a 12 volt alternator on it and has ran just fine for the last 3 years. No problems getting spark or anything. The coil that was on the truck is a generic 12v tractor coil, but has worked just fine. The replacement that I got has a part number 2-5195 and looks exactly like the old one except it has writing on it. Something about adding a resistor. I have no idea what it wants me to do since the old one worked just fine.

Something else that I'm confused about is the instructions I found online (very vague instructions that I think are for this part) and the instructions in the truck manual make it sound like the positive wire from the ignition switch goes to the positive lead on the coil. Then the negative lead on the coil goes to the distributor. The problem is... this is backward to how the last one was hooked up. I took pictures just to make sure and these instructions tell me to hook up the new coil backwards compared to how the last one was hooked up. The old coil worked just fine.

The replacement coil didn't produce any spark either. Just to make sure it was getting voltage I checked both sides of the coil to the engine block and it read over 12 volts on both leads. Then I had unplugged the main spark plug wire that goes from the coil to the center of the distributor from the distributor and held it to the engine block to check for spark while he cranked the engine and there was no spark.

What are we doing wrong? I have no idea what to do next. We cleaned the rotor button and the points, but I don't think it matters because there's no spark getting to the distributor as far as I can tell.

Here's a link to some pictures of the whole set-up with some descriptions on each picture.

https://imgur.com/a/ffq79ST