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Got a strange one going on. Over the past 2 days I noticed my turn signals (OEM) will initially flash rapidly but once I roll off the throttle and begin to make a turn they slow to a normal rate. I was thinking bad connection or bulb, etc. I checked everything tonight and all checks good on the wiring/bulb side. With the ignition on and the bike not running the turn signals operate normal. I began to check battery voltage with a Fluke VOM. I have a lithium battery and it reads 13.1 VDC with the ignition off. OK, so I start the bike and the voltage goes up to near 14VDC everything seems normal in my mind. I start to think when the turn signals malfunction the rpms are up so I tested the voltage with the RPM's up around 2500-3000 and the voltage drops to 9VDC. I don't know $hit from shineola when it comes to motorcycle charging systems but I do know electrical. I rode for over an hour today so it isn't enough to stop the spark because I made it home and the battery is fully topped off. Any suggestions would be appreciated. Voltage rectifier/regulator maybe?

Thanks,
Jim

I'll start.

Hmm. Let's think about this. When the load (current flow) Through the signal leads is not as high as the DR thinks it should be, the signals will blink fast. This is the reason people wire a resistor in parallel to LED signals.

Next person in line, speak up..

Ya, I'm frazzled on this one. I just have the stock turn signals and no led's except the little license plate light from Procycle. I don't thing that would be causing any problems. I sure hope it's not the stator. I will sleep on it and dig into it more tomorrow after work.

If it's just happening on one side it might be a bulb that is disconnecting under vibration

Why would the voltage drop to 9 volts when the RPM is up?

It could be the regulator but I would suspect the stator first. You need to check the testing procedure in the service manual. The stator puts out 3 phase AC and can be measured directly between the 3 yellow wires on the left side of the bike. The manual should have a spec but it will be something like >60vac at 5000 rpm.

So before the coffee wears off, I was thinking about this more and I am leaning towards the regulator not liking the lithium ion battery that I installed. I read somewhere that older style regulators actually rely on the old lead acid style battery as a capacitor of sorts. I wonder if changing to a mosfet stlye regulator would solve this problem. My gut tells me the stator is fine since it is charging at idle but when rpm's are increased the regulator is failing to handle the increased power. I am just thinking out loud at this point.
OK, I have a real dumb question. Does the DR have 2 charging systems? One for the lights/accessories and one for the engine electrical? Like I said before engine electrical is not my strong point. If so, this could explain why the bike continues to run strong under low voltage on the lighting side. Does the voltage regulator have anything to do with the spark plugs? Again, I am clueless here. My guess is it doesn't. Thanks again for any help.

The stator makes maximum output right around 1500 RPM. A healthy charging system will slowly drop voltage as RPMs are raised but will stay above 13v in the upper revs.



Yes, the ignition is powered by a separate stator coil. The bike only needs a small amount of battery voltage present to power the kill circuit in the CDI box.

Thanks for the input. I will be tackling this more when I get off of work tonight. Unless my brain is fried the way today is already going.

I would lean toward regulator myself. although first do the VERY basic and confirm that all your cables (particularly your negative battery lead) are clean and tight at BOTH ends. poor connections also create similar issues.