no electrical - 1981 chev 4x2 pickup

The main battery cable goes to the starter. On the same terminal on the starter should be 2 or three more wires. These carry the power to fuse box, ignition switch etc. In these wires close to the starter should be fusible links, a wire that acts as a fuse to protect the main harness. They usually have what looks like a miniature "rubber can" in the center of them On Fords they were located at the fender mounted starter solenoid. Fuse links can be replaced and are sold at most auto parts stores. They require splicing to the main lead, should be carefully soldered, and shrink tubing used to seal them The rather useless device as you describe it is simply a distribution junction box.. The alternator main lead used to go to the starter main terminal, now it often goes to this point instead. The main lead to the fuse box connects there as well, and usually the power wire to the headlamp switch. If you have no power there, the problem is between the junction box and the starter. Make sure you get the correct links. Too small a rating and it blows to easy, to high a rating and it wont do the job it is supposed to do. I have seen the harness come unclipped from its holders and fall against the exhaust manifold above the starter shorting out and then blowing the fuse links, check for this as well.. Old age can cause them to fail as well.

Whitelightning

I had the same problem just last week with my 86 chev. it was the fusible link on the firewall at the distribution block. turtle