78' F250 Wiring Short

I have been chasing a brake and blinker short for years. I have dealt with all the bare wires, bad sockets, and abraded wires I can find, to no avail. I have heard that these trucks sometimes suffer from a defective Fuse Block. Has anyone ever heard of this? Any suggestions are welcome.

Thanks.

I had this happen on a 1966 Pontiac. If you take a test light and press on the fuse and the power comes on and off this is the problem. I cut both wires to this fuse and purchased an inline fuse holder at the parts store. I installed this with a new fuse. It lasted as long as I owned the car. I seriously doubt you will find a new or used fuse block. I unbolted it with the battery disconnected so I was sure I had the correct wires. Other wise pull it and look for corrosion or a cracked terminal.