updating... looks like when I move the Stop light fuse around at the box I get power to my Orange wire (brake light switch) and all works from there. Not sure what to think about a that... could that be a loose connection behind the fuse panel?

 

Could be corrosion on the terminal or bad connection internally.Is this the original fuse box and wiring?

 

I'll go with corrosion on the fuse clips or broken fuse. Clean them up with a wire brush and put a fresh fuse in.

 

I too think the clips and/or fuse ends might have corrosion and possibly too maybe inside the fuse, the fuse element is broken and once decent power is pulled though it, the element heats up some and a connection get's broke between the element and an end cap. I had this issue years ago with a batch of fuses and was a really strange one I never came across before.

Here is the backside of a 73 Nova fuse block and you can see that the battery side of the clips are on a buss and then the fused side has a wire crimped onto it. I really doubt it is on the backside BUT who's to say sometimes.

The constant portion has the large red wire which goes to the battery and then the orange wires a little to the left go to things like the stop/hazard circuit, the courtesy/lighter circuit, and the tail lamp circuit.

Jim

 

Spot on Gents, you were correct. I have attached a photo, see stop fuse position. Overall, the harness looks to be fairly new but somehow it got wet. As suggested, I cleaned it up with a wire brush added a small amount of dielectric grease to the area and was back in business. I love this forum and I sincerely Appreciate the insight and knowledge. Happy Holidays to you and yours!

 

Thanks for posting your solution, you probably helped another Chevelle person!

 

Looks like you need to spend some time and clean all those terminals, make sure you unhook the battery! 👍