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Turn signals make lights dim...

616 views 5 replies 4 participants last post by  TeeTee  
#1 ·
I know a little dimness is normal on most bikes, but on my 99 R6 its really bad. If you are behind me withthe signals on, it almost seems like when my signals flash, i'm off and on the brakes. Of course this is only during idle, so its not that bad or dangerous...but still...My battery after charging measures around 12.6V. It goes up around 13.5 when my engine is revving.
 
#6 · (Edited)
You can test your battery if you have a voltmeter. Connect the meter up and turn on your signals. If the battery voltage only drops by a tenth or two of a volt then the battery is OK. If it drops by much more then it's on the way out.

But it sounds like you've got some wireing issues. Some bikes switch the positive side and feed the lights. Others switch the ground side and run the power through the light first. In the first case it sounds like you've got a dirty or corroded ground connection. In the second it would be a dirty or corroded positive feed.

You can test for that too. Note the voltage drop at the actual battery posts and then start checking some other spots. For example leave the positive lead on the battery positive post and move the negative along the ground path. Check the wire going into the ground connector on the battery. A bigger variation there means the wire crimping is corroded and is acting resistive. This being bad will also result in weak starter cranking. From there check the voltage at various points along the wire path to the lights looking for a point where you find a significant drop in voltage as the lights blink.

The fact that your neutral light dims when the brake light goes on tells me that your bad ground or bad positive (depending on how the lights are fed) is close to the battery as it's affecting the wires going in both directions.


On my old Ducati I was running into what I thought was a weak starter but I had a new battery so I knew it had to be the connections. I uncrimped all the connections, cut down the wire length of the leads to the solenoid and starter, filed the insides of the crimp connectors to bare clean copper, cleaned the strands of copper of the wire ends (they were damn near black with corrosion), recrimped and soldered all the ends of the positive supply and ground return for the starter circuit. After that the starter damn near threw the engine out of the frame in its eagerness to spin the engine.