So, I've gone through both the Honda and Haynes service manuals, and cannot figure this one out. The headlight simply does not work. Here's what I've found/tried so far:

1. Replaced bulb (and continuity checked bulb)
2. Continuity checked the dimmer switch
3. Continuity checked the wiring harness, from the bulb plug to where the last molex plug can be probed.
4. Checked 10A fuse under the seat.
5. Battery is at ~12.1 V... pretty low. Been sitting for a while. But the bike still starts.
6. Checked the voltage at the bulb plug/harness: 0 V. Should be ~12 V here, no?

I took the rear fairing/cowling off, being there's a bunch of electrical components are relays back there. Is there a headlight relay on these bikes that might be bad? I couldn't find anything on relays in the service manuals.

Any help is much appreciated!

 

upon some googling, some people say there can be a problem in your starter switch? Apparently one of the 3 wires likes to come loose.

CBR 600 F4 Headlight relay? - Honda Motorcycles - FireBlades.org

And im pretty sure there is no relay on your bike.

So id check out your switch.

 

Dirt is probably right. Go with the starter switch. You can look at this for additional info.

https://cbrforum.com/forum/cbr-600f3...issues-126844/

 

In the F4 section, we've had threads about this. The starter switch can be problematic w/ age. Often times, it simply needs cleaning.

 

that happened to me last week, and as idodirt has said in previous threads, its either the dimmer switch or starter push button. mine had a lead that broke loose on the starter button. only took a few minutes to fix it.

 

Indeed, it's the starter switch assembly! I poked around inside, and the headlight flickers on and off as I poke. Is there an easy way to take apart the right handlebar switch assembly without taking off the throttle cable from the handlebar? I'm going now to attempt the fix, so maybe I'll have it fixed by the time a reply comes...