Nuetral light doesnt work. bike wont start in gear. shifting issues

[tbagginz]

So my nuetral light stays on all the time on my 91 honda nighthawk 750. I know there is a million of these questions online but they all have the same answer. Everyone says its the gear position switch. Well I tested mine and and its good, so.........
Im looking into other ideas. Id love to test the system and see if i have a short to ground but the wiring schematic i have is junk.
I realize that I could just disconnect the bulb or whatever but would rather not do that untill i actaully know what is wrong. After that, then i can re access the situation.
Can anybody shed any light on the subject?
Thanks!

 

[Sonreir]

Re: Nuetral light stuck on. 91 Honda Nighthawk 750

Neutral on the Hondas is controlled by the light green/red wire leading from the bulb. In a bike as modern as yours, it probably passes through a diode (in conjunction with the clutch switch wire) to the neutral switch. The color may change as it passes through the diode. Usually it loses the red stripe and becomes just a light green. It may also stay light green/red. You'll need to check. The neutral wire then usually connects to the same plug in the engine as the alternator and is almost always situated right next to the oil pressure wire, which is blue/red.

Anyway... the neutral wire should have continuity to ground when the bike is in neutral and no continuity when it's in gear. This should be verified with a multimeter.

Look good so far?

 

[tbagginz]

Re: Nuetral light stuck on. 91 Honda Nighthawk 750

Neutral on the Hondas is controlled by the light green/red wire leading from the bulb. In a bike as modern as yours, it probably passes through a diode (in conjunction with the clutch switch wire) to the neutral switch. The color may change as it passes through the diode. Usually it loses the red stripe and becomes just a light green. It may also stay light green/red. You'll need to check. The neutral wire then usually connects to the same plug in the engine as the alternator and is almost always situated right next to the oil pressure wire, which is blue/red.

Anyway... the neutral wire should have continuity to ground when the bike is in neutral and no continuity when it's in gear. This should be verified with a multimeter.

Look good so far?

Thanks for the description! I took a ride on my bike this morning and realized that not only is my neutral light stuck on, but my bike wont start in gear, even with the clutch pulled in. So I figured it was time to just check everything. Heres what ive come up with.......
-Neutral switch is good
-clutch switch is good
-side stand switch is good
-all wires between all components (with components disconnected) are all good. no opens. anywhere!
maybe the diode or the ignition control module is messed up? I dont know where to go from here

 

[tbagginz]

Re: Nuetral light stuck on. 91 Honda Nighthawk 750

update
I pulled the tach apart and found that somebody swapped the tach light with the Neutral light. What the???
did I mention I just bought this bike?
So, let me change my initial concern.

So now, the Bike only starts in neutral, it wont start in gear or with the clutch pulled in, and the Neutral light doesnt work, at all

Guess Ill start over with the diag haha

 

[tbagginz]

so it seems ive fixed the nuetral light! The PO had the bulb swapped with the tach light housing bulb. And now suddenly the bike is now starting in gear with the clutch pulled in too???
The bad news is, is that now I realize i have a shifting issue.
Sometimes, 1st, neutral and 2nd are all clicking in really good, then suddenly, the shifter gets bound up and you cant find any gears anymore. Its done the following to me but doesnt really click into any gear while its happening
-shifts between first and second with no nuetral in between, but nothing above 2nd
-shifts between nuetral and second and up, but no 1st to be found
-shifts between 1st and nuetral but no 2nd

its acting like its out of adjustment maybe?, im gonna remove the linkage tomorrow night and try and adjust it and see if it helps

 

[xb33bsa]

that wiring stuff gives me a headache ,and even reading a little bit there just now started one, almost
you are on the right track, linkage first and make it so in the static position you have it as close to 90 degrees at both ends of the link rod as is possible
when 90 at both ends it is perfectly balanced, up down same force same travel
minor deviation is ok but they are almost always designed from oem to be at 90's

 

[tbagginz]

Good news!
So I adjusted the shift linkage and found out it was off one tooth. The gears all shift nice and crisp afterwards. A nice solid click in 1st, Neutral and 2nd. Its also now starting normally with the clutch pulled in and the nuetral light is working normally.
Looks like its a home run. Thanks for the help!