Hoping the brain trust here on the board can help me before I'm left spending hundreds at the dealer having them unscrew my wife's bike--naturally it's a faired model so at least an hour or more worth of shop labor would be taking all the tupperware off so I'm anxious to see if I can isolate the problem myself.
Quick history lesson--I bought this bike used with less than 400 miles on the odo; it's worked swimmingly for a little less than a year and slightly less than 2K miles...but last week it started acting up. The original owner had apparently done quite a few DIY electrical mods. There were originally a pair of running lights with an activation switch set under the fuel door...he pulled the lights before selling the bike so only the pigtails remain zip tied to the frame and a non-functional switch still sits idly under the fuel filler compartment door. There's an OPT7 HID headlight under the fairing, the ballast is attached to the frame just above the headlight assembly. The headlight is wired to a Fiam superhorn mounted under the left side speaker cutout; the horn is wired to one of those modulators that pulses both the horn and the headlight when the horn button is pressed.
Everything appears to be wired appropriately through a relay that's sitting next to the battery...I can't tell if there's yet another relay hidden somewhere under the fuel tank fairings because I haven't gotten that far removing the plastics just yet (having some trouble getting the front side cowling off). The electrical installation looks decent enough, and as I said, it's worked fine since last summer up to a week ago, but there's quite a bit of electrical wiring snaking around under the main fairing so it's hard to follow the wires back to where they originated...I'm not even 100% clear where the original headlight connector is anymore if I just wanted to just pull the HID and put in an OEM bulb.
Here's the problem. The bike starts fine, runs fine, all other electricals work fine, but sporadically starting a week ago, the HID headlight won't turn on. Infuriatingly, sometimes when I turn the ignition key, the light DOES come on just fine as it should--and it stays illuminated before I press the starter to get the engine going. Other times though, I'll get a short buzzing sound right after turning the key, the light will ignite momentarily, then go dark. If I try the key a few more times, the buzz gets shorter until after 2-3 tries, it doesn't make a sound at all, but the light doesn't ignite even slightly either. Then if the bike sits for a bit, the headlight might ignite just fine, or it might make that quick buzzing sound and restart the "almost light-up procedure" mentioned above.
I've removed some of the plastics around the front enough to tell that it doesn't sound like the buzz is coming from the HID ballast, nor does it sound like it's coming from the relay sitting back by the battery--it sounds a bit like it's coming from right underneath the fuel tank near the front of the bike...but I can't be certain. I've uploaded a quick video snippet of the offending sound/light problem. You have to turn the volume up just a bit to hear the buzz over the sound of the key click because it happens almost right away and it's fairly quick, but you can definitely make it out...sounds like one of those old piezo buzzers to me.
Obviously I can't have the bike on the road without a headlight. I've pulled each of the electrical connections to the headlight/horn modulator and relays that I can find; I've cleaned and treated the contacts with some dielectric grease and reseated them. I have the bike sitting on a Battery Tender junior. I do notice that with the tender connected, even a quick turn of the ignition key when the light DOES come on immediately throws the charger from maintenance mode (steady green light) to charging (blinking green). Could this just be a battery in need of replacement (the one installed now is a Yuasa YTZ12S)--that doesn't feel quite right because the bike starts up just fine and I would think a starter motor has a heck of a lot more draw than an HID igniter.
I don't have any experience with relays so I don't know what a bad relay sounds like, and the ones that I've heard buzzing on Youtube don't sound quite like this one...and I've NEVER heard the buzzing continue if the light DOES ignite properly and stay on as shown in
I also don't think it's the main relay sitting back by the battery...but I suppose I could just as easily replace that one just to be sure. Are there other relays under the tupperware at the front aside from the ones in the fuse box by the battery? Is there a relay in the fusebox in particular I could replace just as a troubleshooting step? Could this sound be indicative of some other problem? I would appreciate any advice or assistance...thanks!