84 C10 fuse box problems

[Slammed84]

My 84 has been down for a couple years, luckily I have a garage to park in. Started a 496 build for it but have run out of money for now. My problem is when I tried to start the donor 350 I put in for the time being, I got nothing. After a bnch of wire chasing, I concluded that I wasn't getting power from the fuse block to the ignition switch.

By simply jumping a keyed source from block to ignition switch solved the problem but I really would like to fix the problem instead of having a jumper wire installed. The factory harness is perfect, never been messed with at all.

Im just confused because when it was first parked it would start with the key no problem. Im guessing corrosion?

Anyone had any similar issues/fixes?

Im dreading having to replace the fuse box for one stinkin wire, I wish it would've been something alot less important.