Ducati Monster Forum

Moto Board => Tech => Topic started by: WhiteStripe on July 05, 2009, 06:09:45 PM

Title: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 05, 2009, 06:09:45 PM
Ok, so no police brutality, but my friendly neighborhood police office just pulled me over and let me know that i have NO rear running lights.  He was actually very cool about it - first positive police experience of my life...

can anyone help me trouble shoot the following.

When bike is on (running or not) I have functional headlights, blinkers and brake light BUT when blinker or brakes are not turned on / engaged the only light that is working is the headlight.

No taillight, no license plate light and none of the blinker lights are on (which i assume the should be?).  In other words, just driving down the street and bike is dark in the back unless i hit the brakes or a blinker.

Checked all fuses and they are fine. Really need some help on this, stuck without a car for the week.

TIA

Tim

Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: ducpainter on July 05, 2009, 06:24:59 PM
The directionals don't light unless they are turned on.

Have you checked the bulbs?
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: Spidey on July 05, 2009, 06:29:09 PM
If you have a tail chop (and therefore have likely removed the license plate light), it's probably just a blown tailbub.  Two screws, one on each side, will pop off the red cover.  Push the bulb in slightly and twist.  You can check if one of the two filaments is dead.  Don't screw the screws back in too tight.  They break easily in the plastic.

OTOH, if you license plate light isn't working (and you didn't get rid of it through a tail chop), that probably points to something different than a bulb.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 05, 2009, 06:39:24 PM
No tail chop - bike is totally stock on the back end.  Am going to check the bulbs.

Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 05, 2009, 06:47:51 PM
So my bulb is good. 

The bulb has two filiaments, when break goes both light - i am assuming that on one lights for just the tail light, so i am assuming that the electrical signal is f'ed up.  Just not sure where to start tracing it back, or maybe a common problem area to look for.

Thanks so much for any help or thoughts.
Title: Re: Need some help with weird electrical issue (includes tale of police brutalit
Post by: billg69gmc on July 05, 2009, 07:17:11 PM
Is this the bulb that has two stepped pins for the socket? If so, is it put in wrong?
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: greenmonster on July 06, 2009, 01:01:55 AM
Had something similar on my (carbed) bike.
One earth cable to rear light was semiworking.
Check/wiggle all rear, incl ind, earth cables.
Title: Re: Need some help with weird electrical issue (includes tale of police brutalit
Post by: WhiteStripe on July 06, 2009, 03:24:18 AM
Quote from: billg69gmc on July 05, 2009, 07:17:11 PM
Is this the bulb that has two stepped pins for the socket? If so, is it put in wrong?

think it is fine - it was working ok in the same position last week.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: Porsche Monkey on July 06, 2009, 05:20:17 AM
I would put a bulb in it. Just because that one appears okay doesn't mean it is. Any auto parts store should have one.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 06, 2009, 05:39:04 AM
Quote from: Ducaholic on July 06, 2009, 05:20:17 AM
I would put a bulb in it. Just because that one appears okay doesn't mean it is. Any auto parts store should have one.

yeah, but the bulb works when the brakes are on and the license plate bulb is out too...

I am going to start unplugging and replugging from the tail light back and see what happens.

This is such a PITA because i am without a car for this week and will need to ride at night.

Thanks.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: Porsche Monkey on July 06, 2009, 07:32:29 AM
I would still replace the bulb because its cheap. Next step would be checking everything with a volt meter.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: corey on July 06, 2009, 07:57:13 AM
Quote from: WhiteStripe on July 05, 2009, 06:47:51 PM
So my bulb is good. 

The bulb has two filiaments, when break goes both light - i am assuming that on one lights for just the tail light, so i am assuming that the electrical signal is f'ed up.  Just not sure where to start tracing it back, or maybe a common problem area to look for.

Thanks so much for any help or thoughts.

Sounds like the bulb is in backwards...
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: teddy037.2 on July 06, 2009, 08:10:39 AM
+1 on the bulb
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: dbran1949 on July 06, 2009, 06:36:36 PM
There are two filaments in the tail/brake light bulb. The brake light is the brighter of the two. The tail light should not light when you activate the brake as you described (either switch foot or front hand). It should be on whenever the headlight is on.

Sometimes one filament breaks and falls across a working filament and lights as you describe
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 07, 2009, 05:49:01 AM
Quote from: corey on July 06, 2009, 07:57:13 AM
Sounds like the bulb is in backwards...

Interesting thought.  I actually flipped the bulb around backwards for kicks and in that position it lights when ignition on (but doesn't change with brake actuation when in backwards).  Guess electrical is fine and (as everyone has said) it is the bulb - hopefully good news.

Must be something wrong with one of the posts on the bulb - going to get a new one today.  Any suggestions on replacements?

Thanks to everyone for the help.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on July 08, 2009, 09:24:16 AM
Well it was a loose connection on the license plate light and a bad bulb (as pretty much everyone said).

Thanks for the help all - I really appreciate it.
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: tobyseattle on September 12, 2009, 09:31:19 AM
Same thing happened to me--minus the police.  Both tail and license plate lights out, but brake light worked, tail bulb looked fine, fuses fine.  I too went down the path of thinking there was some weird electrical issues.  Read this thread, replacing both bulbs fixed it. [moto] 

Thanks DMF for saving me way too much time overthinking the problem [beer]
Title: Re: Need some help with weird electrical issue (includes tale of police brutality)..
Post by: WhiteStripe on September 14, 2009, 05:13:37 AM
Good stuff.

My plate light is still on and off - but that can wait til winter.  Glad you got yours sorted.