Headlights dimming

[ryanschoebel]

Bit of a dumb questions here.I know a bit is normal, but it seems excessive. Bike starts and runs fine, and iI recently added new electrolyte to my battery. However, my headlight, and dash lights brighten considerably whenever revving throttle even a little bit, and go back to much dimmer as soon as throttle is released. Is this normal, or symptomatic of something weak/going out?

Sorry for the dumb question, I just know on a car, that means either weak battery, or weak alternator. I feel like battery is okay, because I get solid cranks, even after sitting. Could it be alternator, or maybe I need a voltage regulator? Any thoughts are appreciated!

[FJmonkey]

Two things that make this normal. The alternator does not normally produce much energy at normal idle. Normal running engine revs is when the battery gets recharged from starting. The other is the head lamp is not powered directly to the battery. Voltage is lost through the wiring harness. That is why many here have added a relay(s) to power the head lamp and another to get full voltage to the coils for a proper spark at the plugs.

[Troyskie]

What Mark said

[red]

Bit of a dumb questions here.I know a bit is normal, but it seems excessive. Bike starts and runs fine, and iI recently added new electrolyte to my battery. However, my headlight, and dash lights brighten considerably whenever revving throttle even a little bit, and go back to much dimmer as soon as throttle is released. Is this normal, or symptomatic of something weak/going out?  Sorry for the dumb question, I just know on a car, that means either weak battery, or weak alternator. I feel like battery is okay, because I get solid cranks, even after sitting. Could it be alternator, or maybe I need a voltage regulator? Any thoughts are appreciated!

ryanschoebel,

This could be as simple as dirty battery connections.  You can get wire "toothbrushes" at the auto parts stores (or use any fine-wired brush).  Clean the wire lugs that bolt to the battery, and the battery terminals also, so that you have clean, shiny metal bolted to clean shiny metal.  Wire-brush clean or replace the battery bolts as well, if corroded.  Give the battery a full charge from a decent charger (because the battery may be run down a bit, now).    If the problem remains, there is (as noted above) a mod to add a relay that powers the headlights.

If you do not have a Battery Tender, they are very good for the lifespan of your battery.  Any automatic charger with a "de-sulfating" cycle in it will do the job as well.