Originally Posted by second 70
Tjp 70 Cuda here's a couple of pictures I've found online. The fuse box and bulkhead appear not to connect.

The fuse box looks to be feed from 2 wires coming from separate harness that plug in to lower terminals.


The for sale harness lets you hover over it to see it more clearly.

https://www.partshound.net/product/...y-oe-dash-harness-wcorrect-20-tach-wire/


Back of fuse box

https://timschallenger.weebly.com/blog/back-side-of-fuse-block-after-re-work

As mentioned, not overly familiar with them ( Been a few years wink )
I would check the alternator output VS. Battery as mentioned and start working your way inside until you find the culprit(s). might start with the Ammeter terminals as they are known to loosen over time. If no luck there, then start at tthe battery and check each connection along the circuit. keep us posted beer

www.tandmautomotive-omaha.com