horny bike when wet

[oze]

OK this has now happened to me 3 times.

 

The horn sounds after the bike is wet. First time after rain showers when it was parked while I was in a coffee shop. Next 2 times after I washed it.

 

So I assume the water is shorting some wires... but where?

 

It does not happen immediately but after say 10 minutes. So this leads me to think the water has to trickle down to a place where the wires are exposed and the circuit can be made.

 

basically I have to remove the fuse and the next day after riding or leaving in the sun it dries out and I can put the fuse back in.

 

Maybe the switch on the handlebar?

 

Any ideas anyone? Anyone had this happen?

 

Don

[tazplas]

Can't help on this one except to say it's definitely creating a short in the wiring somewhere. Check your switches and your connections near the horns.

On another note, I had the complete opposite after i washed it one day. Horn sounded garbled. Water up its nose so i found out.

 

Good luck

 

Cheers

 

Steve

[T__]

Don, being a police bike could complicate or at least make troubleshooting your problem a bit more difficult..

 

First off,, does your bike have any sort of anti theft system on it? If so start with that as there are electronics in most anti theft systems that could be low current water sensitive..

 

Assuming your horn is not somehow interconnected to some police system or an anti theft device then that doesn’t leave much to go wrong..

 

Is the fuse you remove the #4 fuse?-- Assuming a stock RT horn system it should be..--- If so that probably means your horn relay isn’t the problem as the relay part that actually honks the horn is not powered directly from the #4 fuse.. Only the control side of the relay is powered from the #4 fuse. So that leaves the handlebar switch or wiring going from the relay to the handlebar switch.. Seeing as that relay is a basic 12 volt DC controlled device (probably takes at least 8 volts at a reasonable current to hold the relay engaged) would probably mean simple water itself would not have a low enough resistance to trigger the relay.. That somewhat eliminates the wiring shorting unless it is in a spot that holds road salt or road debris..

 

My guess would be the handlebar switch itself as that is sealed enough to possibly hold both moisture & salt or other conductor type material.. Keep in mind this is only a guess & if that is not a civilian type horn system or something else is interconnected to the horn (like an antitheft system) then all bets are off..

 

You can try electrically troubleshooting the horn but lacking access to either the disconnect for the handlebar switch or taking the entire thing apart it might be easier to try some non intrusive testing.. First try simply tying a plastic bag around the handlebar horn switch assembly while washing the bike or parking in the rain.. If that eliminates the horn issue then you will have a pretty good idea of where the problem lies.. (OR) maybe try just wetting the handlebar horn switch & handlebar switch assembly (might take a few tries & multi wettings).. If that sets the horn off then again you know where to look first..

 

 

Twisty

 

[oze]

thanks twisty1. Yes it is the fuse #4 and I pulled off the side panels and cannot see any extra wiring involved. I taped around the clip to the horn itself.

 

Another guy also suggested the plastic bag on the handlebars. What you say about the switch itself makes sense. And it does look complicated to pull apart so maybe squirt a bit of WD40 into there and see how I go.

 

Over here we don't get ice and snow so no road salt. But I guess we do get more sea air and I live close to the coast.

[oze]

OK finally a solution. Put the bike into a reputable beemer service shop. After (I kid u not) several hours they found out someone had previously pulled apart the junction box that takes all the wires from the front into the box and out to the fuses. In doing so they had lost most (all?) of the rubber seals that protected the wires. So this meant water can leak in and create a circuit and set off the horn. Who ever did the work to decommission the RT-P wiring - please contact me so i can send you a reward.