Topic: 15amp fuse blows when I connect the battery

[Ujeni]

Hi everyone,

First-time poster, long-time lurker and on my second cb750. A 74 to be exact.

My k4 was a yard find. It sat for 18 years. After a day or two, I had the engine running. But, starting a day or two ago, the 15mp fuse (not the one in the fuse box, but the lone 15amp fuse) blows whenever I connect the battery. I realize I am missing the little fuse holder that the green and red wire are supposed to connect to. I'll get one once I have the bike running.

My electrical knowledge is rather low. I checked my ground cable from the battery to the frame and just behind the seat latch. Both appear fine (no resistance according to my little meter). Here is what the electrical stuff looks like (you can see my 15amp fuse in there):

Can anyone give me some advice on how to track down the issue? I did try disconnecting the regulator...but with the same result; the fuse blew as soon as i connected the battery.

Any help would be appreciated!

[DH]

Not sure what that green wire goes to, but you probly ought to trace it to see where it goes. Suspect its an un-used ground (for your particular model). That fuse has been added by a previous owner I'm guessing, cause a stock k4 won't have it.
Most (if not ALL) green wires on the 750 are grounds, which obviously, shouldn't be connected to any power source. 750's DO
have an auxilliray wire (small red spade connector) as part of the battery positive cable
which is NOT used on U.S.A. models if memory serves me.
Might try just pulling the fuse and seeing if everything still works
without it. Is it possible someone just accidently hooked the fuse to those two wires and that fuse is an add on for another non stock accessory?

[Spanner 1]

Sorry dude buts that pic is funny  ... No fuse there, ever  ... Remove it. That Green connector is on every SOHC bike and is also unused on every bike !... and on a K3 the Red is also unused.... they don't connect to anything, just hang there, normal.

[Ujeni]

So the red and green wires should be disconnected?!

[DH]

I think Spanners right

[Ujeni]

LOL...Spanner is right, I disconnected the fuse and the bike appears to work again.

Wow, I wonder what the heck I was thinking!! 

Thanks guys. Be assured, I will return with more questions once I start my restoration. Hopefully, the next one won't be so stupid though!   

[Spanner 1]

Generally speaking, Red wires on your bike carry 12v + from the battery to the ign. switch... all Green wires are Ground, so the two would never connect directly together  or 'Bam', dead short and smoke produced