Topic: Fuse box issue

[eavo44]

I just bought my first bike, a raggedy 76 cb750f.  I plan to gain a little riding experience before tearing it down this winter for a cafe rebuild.  I am having an issue with the fuse box right off the bat.  The headlight stopped working and when I checked the fuse box it apparently had gotten really hot.  The main fuse connecter I think, 2nd from the bottom, had melted out completely and the others had heat damage.  All the lights work except for the headlight.  If I replace this fuse box will that take care of the issue or is it rooted else ware in the electrical.  I am having a hard time finding this part as well because it has been discontinued.  This part was recalled on the 77/78 models for the same issue so I don't know why it wasn't recalled on the 76.  I am dying to get back on the road before it gets cold out.  Thanks for your help.  Ian

[Bodi]

If you search for "fuse box" you'll probably find a lot of info.
The fuse contacts and the fuse ends get corroded and the connection points start to have higher than normal resistance. The amps going through this resistance makes power, which means they heat up. The heat speeds the corrosion, and things get hotter. The "springiness" goes out of the clips when they get hot enough, and the problem gets worse. Eventually the clips melt the plastic box and the solder connections inside, or the fuse itself overheats and fails.
The best fix is to replace the fusebox with one that takes the now-standard automotive plug-in fuses. In a pinch you can (mark first!) cut the wires in the fusebox and throw out the box, then put 1/4" female insulated spade terminals on the wire ends - the push-in fuses will mate with these perfectly. The fuses will just hang there but will work great.

[lone*X]

Yep, use the search feature.  I just looked at "fuse holder" and came up with a really cheap fix.  Check this link:  http://forums.sohc4.net/index.php?topic=20034.0

When you do your winter rebuild you will probably want to upgrade the holder to the spade type.  That is also covered somewhere on this forum.

[TwoTired]

The fuse clips get oxidized/resistive and passing current through resistance creates heat.  Cleaning fuse clips ought to be in routine maintenance on a 5-10 year recurring cycle.  Once the base plastic melts, it's no longer repairable.  Replacement is required.
If the bike has brighter headlights and low ohm coils or any other electrical changes from stock that create more current demand, this also contributes to fuse box/clip failure. 
If you run a fuse nearer to its parting design, it runs hotter by nature. You may need larger fuse ratings.

Cheers,

[eavo44]

Thanks for the help guys! I think I will be able to fix this issue with the info in those threads. Huge help.