I have rebuilt a 1998 cbr600 f3 for use in a buggy project. I am now in the stage were I have put the engine back into the frame and hooked up all the wires, but I can not make the neutral light come on. So I can not start the engine. When I turn the key on, the oil light, stand light, and high beam light comes on on the dash, but no neutral light. I have tried switching the lights in the dash around and still no go, so the light still works. I have tried by-passing the switch and still no go, so I think the switch is fine.

Is does everything have to be just right for the light to come on. Like is there a sequence of switches that have to be on or something for it to register neutral??

any help would be great!!

 

If you bypassed the switch, the light would come on - I would start there.

 

Well, neutral-light is 1/2 of safety-interloc circuit that also includes clutch and sidestand switch. Without those other switches working properly, your ignitor will refuse to fire sparks. However, neutral-light is independent and should light up regardless.


1. Is neutral-light connected to neutral-switch on engine? Trace wires, from cluster, it should go to 3-wire diode, then from there to neutral-switch. Measure resistance of circuit from neutral-light wire at dash to other end down by engine. With red-probe on dash end and black-probe down at switch-end of wire. ohms = ???

2. Switch may be broken. Measure neutral-switch's continuity to chassis-ground. Is it zero-ohms when transmission is in neutral and infinite-ohms/open-circuit when it's in gear?

3. As test, connect neutral-switch wire-end at neutral-switch to chassis-ground. Does neutral-light turn on at dash?


This is 5-minute fix with multimeter, or less in many cases... Some wire's broken or not connected properly

 

Thanks for the info guys! I have already tried to ground the switch wire to ground and that woes not work.
I guess that I will start to unwind the miles and miles of electrical tape and trace some wires.

 

Looks like the switch goes to the ignition control module and via a diode to the dash light - I would look into that diode...

https://f01.justanswer.com/Martin-Ho...505_152825.jpg

also

http://www.minibuggy.net/forum/contr...tion-pics.html

 

Two different diodes. One in ignition-switch prevents hot-wiring and bypassing switch. This is indicated by engine-cranking, but no spark.

Diode in neutral circuit prevents lighting up neutral-light on dash when you squeeze clutch or put kickstand down. Also disables ignition-module and starter-solenoid if neutral-switch, clutch and kickstand switches aren't set right.

Wiring from neutral-switch goes like this:

neutral-switch -> lite-grn -> 3-wire diode assembly -> lite-gen/red -> neutral light

Don't know if there's plug for 3-wire diode or individual terminals. In any case test:

1. unplug diode and jumper lite-grn to lite-grn/red wire to bypass it. Does neutral light go on? If so, diode is bad or wires connected backwards or neutral-switch is bad

2. after bridging, ground wire-end at neutral-switch. Does neutral light to ON? If not, something wrong with wiring in between

 

Diode is part #12 in this diagram - it's most likely taped into the wire harness.

https://www.motosport.com/oem-parts/...3/wire-harness

 

awesome, thanks! So it does have socket. Just unplug diode to remove from circuit. Then bridge those 2 wires and continue with testing neutral light.

 

Thanks for all the help guys!

So I bridged the wires at the diode and the light came on! It would come on in neutral and not come on in gear.
Then I tested the neutral switch with a volt meter and it reads continuity(the tester beeps) when in neutral, and infinite ohms or open circuit when in gear.

So I think that the diode is bad. Plan to order a new one.

What exactly is the point of the diode? Can I just jump it and get on with starting the engine, or will I hurt something?

 

Diode lets you start/run the bike in gear with the side stand down IF you first pull the clutch. It's the "logic" of the protection system to make sure you don't try to drive away with the sidestand down.