Papa,,,you have ignored what Bill said about points, or at least you don't mention it. It's the points, either need cleaned and adjusted or replaced. Do that instead of measuring volts and amps and trying to analyze the numbers. Logic says you have 12V at coil, Jon G condenser and coils usually last a long time and points (or condenser) are usually the cause of no spark.
Also important is to actually be checking spark across a plug's Gap.
This post had no question or issue until there was a no spark condition. Up until then it was a discussion about how chevy wired the truck to accomplish what the diagram says.
You test a coil by looking at the points to see if they are closed or open and get readings each way. But I suggest to stop checking coil. Concentrate only on the points.
You do need to be sure you have 12V to coil postitve when cranking.
I assume "no fire" means no sound or backfire/nothing when engine cranked. I assume "no spark to plugs" means you took a plug out and with plug wire connected, you laid the plug threads on a good ground spot, key on, cranked motor and watched to see a spark across gap, under dark lighting.
Last edited by bartamos; 04/26/2025 11:29 PM. Reason: added last two sentences
