Josh --

"...just lay a bead of solder over all joining connections? Just add a whole layer of solder to it all, avoiding, of course, cross-connecting..."

Not quite. That would result in what's usually called a "cold solder joint," where the solder beads up over the actual electrical connection but doesn't penetrate the connection.

You want to heat the existing solder so it melts and reflows, and at the same time add new solder. You add new solder for two reasons.

First, the new solder will include rosin (or "flux"). As the flux melts, it cleans the oxide from the connections, permitting proper joining of the metals. Also, the flux lowers the surface tension so the new solder will flow into the electrical connection rather than beading up around it.

Second, new solder has a different and better mixture of metals, so it forms a much stronger union than the solder used in the automated process.

"...why is fuse six giving me such a hard time?"

Is this the first failure for that fuse? Maybe it's the wrong value, or maybe the stupid thing simply broke from road vibration. It happens.

Don Foster (near Cape Cod, MA)