Horn Intermittent

My '07 R has two Fiamm Freeway Blasters, instead of the stock beeper. They're wired in parallel using the original power feed, as the ZFE (the Can-Bus body controller) can tolerate the current draw of two horns of this type — the same ZFE was used with two horns on early Hexhead RTs. I installed the horns in 2010, and they're worked fine since, in both wet an dry conditions.

Except for the last few days. I rode out the the Eastern Sierra, and on the way back it rained. At one point during the ride home, I pushed the horn button and the horns sounded...but for only a second or two, then silence. After that, the horns would not sound. After I'd stopped for a meal, however, the horns began working again...but only for a second of two, then silence again. The pattern repeated after the second meal stop, too.

This morning in the garage, the horns work normally, with no time outs when I hold the button down, or press it again and again.

What might cause this? Poor electrical connections at the electrical connections I made?

I got un-lazy, and took out the GS-911. I'm lazy about using it because the PC laptop I use has a won't-stay-charged battery, and it's so difficult to plug in the power block. So sue me.

The GS-911 reported a short circuit in the horn wiring: the fault appeared three times and was not now present. The ZFE did, indeed, cut off the horn circuit three times during the ride home.

Sounds like I should re-do and better protect the wiring.

If you don't spot a physical problem - Can a GS-911 tell the difference between a "short circuit" and load (resistance) that is just too low for that branch of wiring? Maybe the dual Fiamms are right at line line where they may or may not trip the ZFE.
Have a look at http://advrider.com/index.php?threads/relay-required-for-fiamm-freeway-blasters.271578/

After reading the ADVRider thread - and spotting a lot of electrical confusion - my conclusion is - maybe.

I have the same setup David has on his R12R - dual FIAMMs, and no relay. At times I can notice one of the horns isn't really contributing much to the total horn noise output, so I've considered adding a relay, but being lazy I haven't really gotten around to it. One thing that can cause a horn to not sound - and not sounding generally means drawing a continuous current instead of the reduced current that sounding (opening and closing the coil contacts) provides - is the horn mounting. FIAMM horns come with two spring metal piece for each horn to be mounted with. These really must be used. They are part of the tuned resonant circuit the buzzer needs to work right. Solid mounting of the horn will usually cause it to either sound odd, or not sound at all.

So - I'm gonna watch what David does.. if he adds a relay, I'll probably add one too. Be nice if EasternBeaver made a kit for this..

I suspect the overcurrent condition was because of a bit low battery voltage. David - you probably were wearing heated gear when it started raining? Heated grips on? Auxiliary lights on? Low voltage on that sort of circuit can result in it not sounding and drawing a continuous current that probably exceeds the 10A the circuit is "fused" for.. (electronic fuse..) A relay would likely help in those conditions.

BTW - the GS-911 can only report the status of the circuit as seen/reported by the ZFE. The ZFE doesn't have a load display function for the switching circuits unfortunately - it just reports the "state" of the switch.

Don, your low voltage theory would explain why the horns used to work in wet conditions, but didn't during the last ride.

But...the battery (Yuasa YTX14H-BS) is only a few months old, and cranks the bike very briskly all the time. While I had the Gerbings liner on, the only other current users were F&R Skene LEDs, pretty small consumers. Given these and the size of the alternator, I'm not convinced the system voltage was low.

Mary's Rule of Life #4 is "Some things cannot be understood." Perhaps a corollary would be "At least at first."