1998 Kawasaki Bayou 400 4x4 Electrical Issue (Neutral light intermittently turns on and off)

[T37Mark]

HI everyone. New to this forum. I have 98 Kawasaki Bayou 400 with an apparent electrical issue. I have the Clymer manual, but I am not exactly sure where to start. The issue started a month ago and the neutral light would go on and off intermittently. Eventually it went completely off , and I thought it was a shifting issue. I took the case off and checked the clutch and all mechanical shifting components are good, so I think I eliminated that. The switch sometimes works, sometimes doesn't. Last time I tried, I did hear a clicking sound near where the battery is right before the light went out. Does anyone have any ideas where to start? Hoping this is an easy fix.

[jen]

when the light is off can you by pass components (jumper wire ) and get light on. What else does not work?

[Gwbarm]

Switch could be bad but it sounds like a ground issue.

[alexwv1863]

I'm not sure how the carb is on that year, but check the bottom of it and see if there's electrical wires going to the bottom. I had a similar issue where the neutral light would come on and off and wouldn't start all of the time. That wire was my issue. I can take photos and may be better to explain if needed

[T37Mark]

If u could send a picture that would be great

[alexwv1863]

Sorry I took so long. Here's some screenshots of the one I bought. I circled the area that I was talking about. If you can't see what I'm talking about, let me know and I'll go out and take photos of the old carb. I just forgot when I was outside and I wanted to get a reply to you.

[Gwbarm]

The electrical wire appears to be hooked to a carb heater but cant really tell where the other wires go. I thought it might be to an anti drainback valve but i dont see one on the carb unless its internal. I dont see how that would affect the neutral light unless it was grounding out the whole system in which you should notice other more serious problems. I have never seen one with the neutral wire wired into that circuit. 

[alexwv1863]

I'm not sure exactly but I know for a fact that it does affect the neutral light somehow. The reason I say this, is while trying to diagnose the old carb I had, the neutral light wouldn't come on unless the wire had good connection to the metal tip going into the carb. If the neutral light wasn't lit up, the bike wouldn't try to start at all. It was like it was completely dead. I did quite a bit of troubleshooting, and that connection was the main culprit. Bought an aftermarket carb and the bike cranked right up. So I know for a fact a carb like this has to have that wire connected.

[bellarmine]

Hi Mark, Welcome to the forum!

It sounds to me like it's likely you have a bad ignition switch, as the Neutral light is the fist thing that comes on when you turn on the ignition.  The clicking you hear is the Neutral relay at the back which enables the starter solenoid.  Does the neutral light come on and off if you wiggle the keyswitch?  I had the same problem on my 1986 Bayou 300 (almost same machine owned since new), would cut out at high RPM from the load.  We just shorted the switch terminals with a wire and connector and problem went away. 

Check out my 3 posts at this other topic, I show my (Complicated) Wiring Diagram and my Dad's (Simplified) Schematic, same thing.  You can see it's not that complex, power comes from the battery, thru a fuse, to the ignition switch, to the Neutral and Reverse bulbs, then to ground thru the Transmission range switch (reverse or neutral).  No bulb is simply a fault in one of these items.  If it's intermittent I'd check the Neutral/Reverse switch in the tranny (which you say you've done), or more likely the Ignition switch.  The ignition switch turns on Everything, so all the load goes thru it and the contacts wear out over time.

Quick check:  Turn on the ignition, If the neutral light is not on, turn on the headlights.  If the headlights turn on, then it's either not in Neutral or the Tranny switch is faulty / out of adjustment.  I can tell you how to bypass that very easily if necessary.  If the headlights DON'T come on, then bad ignition switch / wiring / fuse from battery.

Hope this helps Mark, let me know if I can further assist!

Bellarmine

 

Edited December 15, 2025 by bellarmine

[alexwv1863]

This is the old carb I took off the Kawasaki I was working on. The connection where my finger is, with the clear end, is what was keeping mine from running. If I could get the connector to make connection with the piece on the carb, the neutral light would come on and crank, but if it wasn't making connection there, nothing would happen. No neutral light, nothing. I put a new carb on and it fired right up. I know for a fact that was my issue. Yours might be different, but if it looks like this carb, check the connection there. Sorry I took so long to get back