Bonneville America Forums Forums Technical Forums General Tech Headlight dims

The p/u coil was replaced, my lights dim/brighten a little with the idle/rev. Will a weak battery put a strain on the system? Can i ignore it and ride for another month? It takes a full charge to 13.6, have not tested with it running. Hopefully can do a r/r next year. My battery is the original 06.

I would do the wiring mod - heavy gauge wire direct from the RR to the battery first. Cheap and easy. Do a search for the RR wiring mod posts.

Your battery is old and probably needs replacing but I don't think it is a factor in the headlight dimming while the engine is running (others with more electrical knowledge may correct me here).

You can also do another very good cheap wiring mod. A direct wiring harness hooking up your headlight directly to the battery. This will give your headlight new life! It will be much brighter and won't suck as much power. These harnesses are available from Eastern Beaver. Plug and play.

Check the voltage at the battery when its running at idle. Then check it at 4000 rpms. Should be a little over 12.5 volts at idle and around 14.0 volts at 4000 rpms.

All headlights will brighten up a bit when you rev the engine. That is normal. It indicates that the charging system is working. Not working, the light stays the same intensity.....dim.

Thank you all. Just wanna ride a bit w/o breaking down.

I went down this road before. You can see my problem & solution here:
Charging fix

I read that and plan on taking your advice and doing it next year, wallet permitting. I don't use my light bar now, just the headlight. Is that paranoia or what?