Ducati Monster Forum

Any idea why my blinkers are fast when the bike is idling/stationary but becomes slower once the bike is moving?  The bike is using LED blinkers from the previous owner.

Sounds like some kind of voltage issue to me, but I'm really not the person to ask.

Worry not, someone smarter will come along soon.

Does the rate of flashing change with engine speed? Do they flash faster when you take off from a stop? Do you know if anything else was wired in when the flashers were switched to LEDs?

What bike?  What modifications to that circuit (LEDs, different flasher...)?  In the meanwhile make sure the charging system is putting out sufficient, but not too much voltage.  You want to see 13.5-14.5 volts at the battery at about 3K RPM.

He says they are  LED...

Check voltage at the battery at idle and then slowly increase rpms to say 5k and watch the voltage. 

Bikepilot is correct.  These are non-stock blinkers.  The previous owner replaced them with LED signals, both front and back.  I don't have a way of measuring voltage, if so, how should I go about doing that?  So basically, when the bike is revved higher, the voltage changes?  Is that right?  I am thinking of purchasing these... http://www.monsterparts.com/p/EE033H/LED+Resistor+Kit.html. (http://www.monsterparts.com/p/EE033H/LED+Resistor+Kit.html.)  Would I need a total of four of these, one for each blinker? [EDIT] Spoke with Jeff at Monsterparts.  He says usually a pair is most likely all I need.  How does the blinker system work any way?  Are all four blinkers attached to each other?

BTW, in the meantime, is it ok to ride the bike like this or will I be messing up the electrical system if I do?

You'll need a multimeter to check the voltage.  You can find them at any autoparts  stores and most home improvement type places
http://en.wikipedia.org/wiki/Multimeter (http://en.wikipedia.org/wiki/Multimeter)

Just hook the correct leads to the battery and set the meter to DC volts setting, and measure the voltage at various RPMs on your bike

If it is indeed putting out too much/too little voltage your regulator rectifier is most likely busted.  It can go in various ways.  One is to stop charging the bike, the other is to cook your battery till it explodes possibly melting a lot of wires in the process.

All that said if LEDs were swapped in without any further modification, I imagine just adding the resistors will solve your issue.  Until you add the resistors the only damage will be fast blinkers.

Thanks Gimpy, what values should I look at at the various RPMs.  Howie states 13.5-14.5 at 3k RPMs.  How about the other RPMs?

Check charging voltage or get the bike to a shop.  A cheap digital multimeter shouldn't set you back more than about $25.  You want to see something at least close to 13 volts at idle.  13.5-14.5 works from 3K to red line.  Low speed reading reading is not be so important and will vary somewhat from year to year.  More important is you are not overcharging, altering the blink rate.  Overcharging will cause other damage.  Get your readings and post them.  Also include model info.

Thanks.  I'll go pick  up a multimeter at my local Harbor Freight.  The bike is an '07 S2R800.

Model: 2007 S2R800

Bike off: 12.74
Bike on: 12.35
1K RPM: 13.5
1.5K RPM: 14.28
2k RPM: 14.25
2.5K RPM: 14.30
3K RPM: 14.30
3.5K RPM: 14.35

I tried measuring with the blinkers on and did not notice any changes in the multimeter readings.

OK, the numbers look good.  It does seem your idle speed is low.  You should be idling at 11-1200 RPM.  It is possible the low idle and low voltage associated with it could be causing the different blinking speed at idle, though I'm stumped why this would occur.  Easy enough to find out.  Just raise the idle speed or adjust the fast idle lever to 1100 RPM and see what happens. 

The chip in your gauges that controls the blinkers senses the current.  If the current is too low, it flashes at double the rate to signal a blown bulb.  As the voltage goes up, the current through an LED/resistor combination will go up too.

I'm guessing that at idle, the current is under the threshhold to indicate a blown bulb - as the revs (and voltage, and current) increase, you go through the threshhold, and it decides it's all okay.

Thanks.  The idle is actually around 1150 to 1200 RPM.  I was able to measure the 1k RPM because I started measuring the bike when it was cold, so I controlled the RPMs via the fast start lever (lever that looks like a choke lever).  I measured the 2.5k to 3.5k RPMs ranges after a couple of minutes using the throttle when she was a bit more warmed up.

Sounds like a logical explanation.  Would there be any problems if I run the bike like this?  For example, will the circuits die quicker?

No, they won't.  It'll just be annoying.  If it were me, I'd add resistors across the LEDs until it stopped fast-blinking at idle.  From the sounds of it, something like 47 Ohm should be plenty.

So I bought resistors and added them to the rear signal connection points, what I notice is that when the bike is just set to "on", they would blink fast.  When on idle, the left signal blinks normally, the right signal starts off fast, then slows after a few seconds.  What's the deal with that?  Why is the left inconsistent to the right?