MC 54 250B / Cyprus 250 Taillights OUT - Solved! By dhull (Read 1,186 times)

[dhull]

I think I've blown a fuse, but I'm not sure where it is and I need help locating it. On Friday night, my taillights and brake lights went out. Rear turn signals work fine, but all red lights are out on the back of the bike.

I've seen photos of a fusebox that fits in a hole next to the battery. My bike does not have a fusebox there. It is just an empty hole. The inline fuse at the battery is fine, so the problem is somewhere else.

[jct842]

MODERATOR fix the damn edit

[jct842]

Is probably a bad connection. The brake light circuit has to work or it would not start. Look for plug loose under there. Possibly a fuse but the tail light circuit and brake light are separate circuits. Also bad ground/

[bhinch]

I had the same problem a few years ago and it was the R/R. Replaced it and everything was back to normal. Enjoy..

[dhull]

New symptom to report: the tail lights and brake lights work with the key on but I get nothing from them when the bike is running.

[Alleyoop]

Your brake lights, and running lights and horn and gauges should work JUST WITH THE KEY ON, they are run off the battery.
Now your headlights might just work when the motor is running.

So are you saying when the motor is running you loose the brake lights and running lights???

[dhull]

Yes. After I start the engine the tail lights and brake lights stop working. They work with the key on but the engine not running.

[Alleyoop]

Sept 24, 2014 16:08:41 GMT -6 dhull said:

Yes. After I start the engine the tail lights and brake lights stop working. They work with the key on but the engine not running.

WOW!! now that is strange because the only thing that would effect that would be the battery since those parts work straight from the battery with the key on. So something is drawing all the juice once the motor starts up and that would be the R/R.

Have you added some electrical item to the scoot have you tested to see when the motor is running Is the battery being charged?
Alleyoop

[dhull]

I haven't added anything to the bike and I haven't checked the battery, but this has been going on for almost a week now and there hasn't been any noticeable drain on it. It kicks up the starter every time without hesitation.

I replaced the R/R about two years ago. I had started noticing black drops of something on my muffler and there was a very bitter smell. The drops were from the black resin of the R/R melting as it got hot. I haven't had any electrical issues until this.

I have a multimeter and can check the battery. What voltage should I be getting?

[Alleyoop]

Revving it up to 4-5k it should register 13+ volts.
Alleyoop

[dhull]

Problem solved. I opened up the back compartment and pulled out the bulb housings. I removed one bulb, turned the key on, started the motor and the remaining bulb worked. I had a spare bulb for my 150 bike that was a different brand and size, so I decided to try it out and it worked also.

The bulbs I had been using that no longer worked were Sylvania SilverStar 1157s. According to the package, the other size (7528) had a lesser power draw, so I got a new package of them, put them in and everything is working again.