Topic: cb750 neutral switch and idiot light

[greenjeans]

76 CB750K

New harness.   Good connections.    When in neutral, the bulb lights bright.  Every time.

However, sometimes the bulb glows all the time - through all the gears.  However, it is only about half as bright - barely on.  When shifted into neutral, it brightens.   Sometimes when cold, sometimes when hot.

My ground connection is solid.  No breaks in the wiring from the switch to where it hits the harness.  The wiring from the idiot lights into the headlight bucket appears fine.

I'm about to switch out a known good switch to see if that fixes things but I have my doubts.

Any ideas ?

[calj737]

There's a few threads on here about aftermarket harnesses and a few idiosyncrasies with them. It sounds as though the gauge light power feed is jumpered to the neutral light, even though the switch is sending a separate signal to indicate "N" position.

Is that even possible?

[martin99]

I had the same problem a while ago. No breaks in the wire to the switch. BUT...
I removed the outer cover sleeve that the switch wire runs through - I guess it has this additional heat resistant sleeve as it runs so tight to the bottom of the motor. This revealed a split in the insulation of the switch wire, exposing bare copper wire which was very green/black and corroded, yet still intact and showing continuity according to my test light. I chopped out the bad portion (about an inch total so I had clean bare wire either side of the splice) and, after sliding a piece of heatshrink up the wire, soldered up the two ends together. This cured the problem instantly, after which I disconnected the wire at the switch and slid a new length of heat resistant sleeve on.