Topic: no neutral light 1977 cb750k

[sandvet]

good afternoon everyone,this is my first time here so i hope im doing this right.I have a 1977 cb750k,it kick starts great,electric starter didnt work when i got it,ive since then got the starter working,but only if i jumper the light green/red wire to the green ground wire at the connector,neutral light will come on and start right up,problem is neutral light stays on in any gear with the jumper wire connected,also if i remove jumper wire and pull clutch in,no neutral light and no start.i dont wanna use the jumper wire,and im having a hard time figuring out.so long story short if i dont use a jumper wire,i have no neutral light and no start,and pulling clutch in doesnt start either.any help would be greatly appreciated thank you for any responses

[flybox1]

Unscrew the wire from the neutral light switch, and with the control switch ON, the N light should be off.  If you ground the wire to the engine case or bare frame, the N light should go ON.

[sandvet]

thank u for the advice,when i get home from work i will try that and let you know,so do i understand you right,if i disconnect wire from neutral switch and ground it to the frame and neutral light comes on ,that would mean i have a bad neutral switch ? thanks again

[flybox1]

correct. 
If it IS the switch...before pitching it and buying a new one, soak it/actuate it in parts cleaner, or kerosene, and see if you can get it to free up.
you might just need to get it moving again.  There is a check ball on the end of it.  You'll see it.  depress it a bunch in cleaner.


Connect the wire to it. touch the ball to the frame.  Light ON...switch is OK to use.

[sandvet]

will do,thank you so much

[Xander^]

ive been having the same issue.. although i took the wire off the switch and touched the frame and indicator light on gauge still didnt work... im also getting not oil pressure light....

gauge lights themselves do work, i connected straight to the battery before install. now im thinking its not my neutral swtich, and maybe the wiring from the alternator or something? .. i've also installed a new mini wire harness that connects from the alternator wires to main harness.

any thoughts?

[BenelliSEI]

Xander...... the oil pressure light and neutral light are both fed by the same power (+) wire. Both lights come ON when the switches deliver a ground. Generally, if neither light comes ON when you switch on the ignition, I’d start by checking that power line. Probably disconnected at the first junction towards the main harness?

[evinrude7]

ive been having the same issue.. although i took the wire off the switch and touched the frame and indicator light on gauge still didnt work... im also getting not oil pressure light....

gauge lights themselves do work, i connected straight to the battery before install. now im thinking its not my neutral swtich, and maybe the wiring from the alternator or something? .. i've also installed a new mini wire harness that connects from the alternator wires to main harness.

any thoughts?

look behind your airbox.  there is a big block connection there. 

[scottly]

good afternoon everyone,this is my first time here so i hope im doing this right.I have a 1977 cb750k,it kick starts great,electric starter didnt work when i got it,ive since then got the starter working,but only if i jumper the light green/red wire to the green ground wire at the connector,neutral light will come on and start right up,problem is neutral light stays on in any gear with the jumper wire connected,also if i remove jumper wire and pull clutch in,no neutral light and no start.i dont wanna use the jumper wire,and im having a hard time figuring out.so long story short if i dont use a jumper wire,i have no neutral light and no start,and pulling clutch in doesnt start either.any help would be greatly appreciated thank you for any responses

Your K7 has a diode to only allow the electric starter to work when the trans is in neutral or the clutch is pulled in. Jumping the green/red to green (ground) bypasses both the neutral switch and the clutch switch. This diode allows the ground side of the starter solenoid to pass through when either condition is met. Sounds like your diode has failed to an "open" condition, failing to pass the ground to both the neutral light and solenoid. There is probably nothing wrong with the neutral switch, neutral light, or clutch switch, just a bad diode. The diode has two wires: a green/red, and a light green/red.