On my 70 jimmy I am rewiring some things after 1 1/2 years so I'm a little foggy on where things went. there is a wire that goes from the fuse box spade labeled unfused ignition to a box that is 1 inch tall by 1 inch deep by 1 3/4 wide. 2 wires come out of the other side. Insided the plastic box is a copper plate where the wires are soldered. I am curious if this maybe was the power to the old AM radio? Does the box make one wire hot all the time and one wire work only with the ignition on? I posted this in the 1st gen forum but no answers so I thought I would try here. Thanks.