Headlight Flickering

[Slv3]

I recently installed a daymaker headlight (JW Speaker) and daymaker spotlights.
The weather was nice yesterday, so I took the bike for a ride. When I got back,
I let it idle in the driveway and the fan turned on. Upon doing so, my headlight began
to flicker. When I turned the spotlights off, the flicker stopped. The bike is an 01
standard with about 11,000 miles. The headlight is not directly wired to the battery
(stock config). Thinking back, I should of throttled up with spotlights on to see if the
flickering would of stopped. I have a new battery that I will install this spring. I appreciate
any feedback.

[Daniel Meyer]

Sounds like the voltage dropped below what the daymaker likes. At idle with the fan on and stock config (no relay for headlight) this would not surprise me. Also idle could be a smidgen low. I set mine at 1000rpm because I end up idling in traffic and running the fan often and want the voltage to stay up...

[Slv3]

I’ll see where idle is and go from there. Thanks.

[Savago]

After adjusting the idle, it may be worthwhile to check:

a) If the battery is not too old (i.e. load test) or a bit uncharged (a multimeter is quite useful for this).
b) With the bike on and idling (after a short ride to warm up the alternator), verify if the voltage is correct.

That will help to identify issues (e.g. uncharged battery, failing alternator).

[Slv3]

Good checklist Savago, thanks!

[MarkT]

Might be worthwhile to wire it so the battery is between the alternator and the lights. It should be a buffer and smooth out the pulses.  Or just install the battery - that's easiest.  Just thinkin out loud.

[Slv3]

Thanks MarkT. Will go that route if bumping up idle doesn’t work. I ran it today and it’s
just under 900.