Even with a dead simple fuseblock like the 65-66 B body, it can be sometimes a little perplexing as to how and what the fuses actually feed, the power paths, and how they are actually fed.
You can't really see what's going on unless you have the block off and can see the back. While the 65-66 chassis manual has a decent description of the cross function, and the block is labeled, if you're like me, it's always a little easier to see it in a graphic form.
I was bored, so I made this up. Who knows, maybe it could help you out a little at some point,
I should note the 65 Chevrolet has differences as seen below. Chevrolet does not have the 14 Brown shunt across the block or the paired 20 Black/Pinks. It has the 20 Black/Pink split and feeding two positions. And has a 14 Black feeding where the 14 Brown shunt would have been on the CP.
A local guy was having problems with the signal lights in his 67 Parisienne, changed the flasher to no avail. He was changing the flasher on the fuse block (for hazard lights), he didn't know there was another flasher in the dash harness for signal lights.
George, all I know for sure is that this type of Fuse box molding was used in many different GM bodies, 64-66. But it's probably certain that every division configured it in their own manner. In 67 it seems the bigger bodies moved to the larger fuse capacity, but the smaller bodies actually kept this style for a while. Buick and Olds bigger cars seemed to have their own style all along.
I think the Chevrolet and CP B Body might be the closest you'll find for obvious reasons.
Would be interesting to see how they changed over the years, and who did what.
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65 Laurentian post, 67 Grande Parisienne 4 door HT.