Nagging lighting problem

[scoothorns]

I've searched the forums and threads but did not find an issue like mine, perhaps I did not look hard enough.

On my ZNENT-B 2008 250 cc scooter (1000 miles), the headlights, instrument panel and running lights don't work. Brake lights, turn signals, and temporary high beam lights (temp switch on HI/LO beam switch) all work fine.

I've tested charging, stator, regulator wires and all seem to have proper voltages. The electrical diagram from the owner's manual seems to be a generic non-specific diagram, with wire colors not matching my actual wiring colors.

For one thing, the famous yellow wire is shown on the diagram to come to the light switch, where power is passed over to the brown wire that powers all these circuits.

However, the tracing of this yellow wire shows it ends not at the right-hand light switch, but on a black box the size slightly smaller than a cigarette pack, where two brown and blue wires (same colors that come to the light switch) are also connected.

I've tested the yellow wire's voltage as it comes to the front of the scooter up the handlebars wire harness and it gives me a 5 V DC as well as a 14 V AC on the same wire. The voltage is regulated as it remains steady (more or less) while increasing the throttle.

I've also tested the light switch and it appears alright.

What I am asking is for some help in troubleshooting this as is now starting to drive me batty! Is that black box some sort of relay or light controller? Am I missing something obvious? What else could be the problem?

I sincerely appreciate any help in this matter.

[larry001964]

I would check the grounds. No running lights has to be somthing they all have in common. You checked the hot. Next would be the ground wires.

[nulldevice]

Many scooters are wired so that the lights you mentioned don't turn on unless the motor is running. Are you checking out the lights while the motor is running?

[scoothorns]

larry001964, thanks for replying. How do I check the grounds? Do you mean the wire used for grounding the headlights and running lights at the fairings? I am not sure I have identified those wires yet.

nulldevice, thanks for your comment. When you say "checking out the lights" do you mean chgecking the voltage at the various wires believed to be involved? The answer is yes. In fact, I get nothing live at all in all the wires coming into the light switch. Obviously I get something live at the HI/LO switch since the hi-beam works with the "Passing" temp switch pressed.

Is it normal to have both 5V DC and 14 V AC on that yellow wire?

Thanks a million!

[larry001964]

Jun 3, 2012 12:01:14 GMT -5 scoothorns said:

larry001964, thanks for replying. How do I check the grounds? Do you mean the wire used for grounding the headlights and running lights at the fairings? I am not sure I have identified those wires yet.

nulldevice, thanks for your comment. When you say "checking out the lights" do you mean chgecking the voltage at the various wires believed to be involved? The answer is yes. In fact, I get nothing live at all in all the wires coming into the light switch. Obviously I get something live at the HI/LO switch since the hi-beam works with the "Passing" temp switch pressed.

Is it normal to have both 5V DC and 14 V AC on that yellow wire?

Thanks a million!

Yes those are the grounds referring to.

[wile]

That block box is probably a Diode, it may be bad or you have a bad ground. Also have you checked your fuses. A lot of 250s have a fuse box for lights and accessories.
Wile

[leo]

Jun 3, 2012 1:31:03 GMT -5 scoothorns said:

I sincerely appreciate any help in this matter.

the only way i could cure my electrical woes was to rewire my ride.
i used direct runs with crimp on connectors and high quality switches.
the only OEM connectors i left on the bike was for the R/R, CDI, and the taillight rear turn signals.

haven't had a wiring problem since.
well, yes i did but it was negligence on my part.
i somehow allowed a loop of wire to hang down around my forks.
this loop got fouled in the fork stops thereby chewing the insulation off and mangling the wire.
blown fuses with dying and no starts.
once i found the problem the solution was simple.