Fuse panel removal, 74 Chevy C20 pickup

[ray_mcavoy]

Sounds like you are on the right track.

Once that center bolt is removed from the under-hood side of the bulkhead connector, the group of connectors for the under-hood wiring should unplug without too much effort. Make sure that center bolt is fully unscrewed ... I think some of them have a snap ring on the inside to prevent them from coming out of the connector, but you should still be able to unscrew it all the way. It might also help to re-install those 2 screws on the inside to hold that part solid while you wiggle / pull on the under-hood side of the connector.

I suppose it's possible that you have a terminal or two inside the connector that has over-heated due to having a poor (high resistance) connection or simply too much current flowing through it at some point. That could have partially melted the connector halves together or distorted them to the point where they will no longer pull apart easily as designed.