Alex687 Posted September 18, 2016 Share Posted September 18, 2016 Forgive me for my lack of knowledge, especially when it comes to electrics, but I am a new rider and this is my first bike (2005 xt125r)I've been struggling with the carb and getting a nice steady idle but that is for another thread. The issue here is the way the headlight is reeeeeally dim at low revs. Haynes says the idle should be around 1700rpm and when I have had it holding idle at that speed the light is incredibly dim (like just a faint orange glow from the filament) I've not used it at night yet but I know that as it is, it wouldn't be safe. It only really gets bright above 3-4000rpm. It's hard to say, but even at this stage I'm not sure how well it would illuminate the road...Reading Haynes, it would appear there are two coils, one for lights, and one for charging. I check the resistance in these coils across the connector pins like Haynes says, and I'd say the resistance is 20-30% above the limits advised in the manual (manual says around 0.6-0.9 ohms and I see around 1.1-1.4 depending on how good a connection I get). I don't know if maybe this is a big problem. The voltage across the battery when the engine is running is between 13.5-14.5V depending on rpm which suggests it's charging ok.On this bike there is no light switch, they are constantly on - when the ignition is on but the engine is stopped, the headlight and tail light are both completely off (the battery is new, and showing 12.7v when not running). The indicators and brake light all work fine with the engine off.Are there any tests I can do, testing resistance between connectors, checking grounds - which ones and how? lolAny help or opinions much appreciated. Link to comment Share on other sites More sharing options...
finnerz89 Posted September 18, 2016 Share Posted September 18, 2016 Firstly, it's normal for the headlight to be a little less bright when at idle compared to higher revs, but probably not as bad as you're describing. Try testing the voltage at the bulb, see what you're getting there. There can be a lot of small gauge wiring in a lighting circuit on a bike that can sap the power Sent from my E6553 using Tapatalk 1 Link to comment Share on other sites More sharing options...
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