Two honks, you're out

[Walter]

Ok, the horn "issue" finally bit me the this morning on the way to work. Normally I don't honk much, but needed to this morning on the way to work but my horn was gone (because I had used it previously in my commute).

 

I can often go multiple weeks without honking, but now twice in one day!!!

 

So, key-on, bike running, honk your horn with a couple of good blasts, wait a few minutes, and try and honk again...I bet you can't....;^)

 

Has anyone come up with an interesting solution?

 

Walter

[codinn]

Hi Walter,

 

The horn is such a strong current draw that if you lay on it for too long the computer will shut off that circuit to protect the wiring. Try multiple short bursts on the horn rather than laying on it.

 

If it does turn off, stop, turn off the key, turn it back on and start up. The horn will magically be fixed.

[roadscholar]

Thanks for the replies. I've known about the oilheads' optimistic speedos, but wasn't aware hexheads were more accurate (more civilized so you don't feel speed as much). Thanks especially Walter. I'd already figured this would be a safe way to gather info but I haven't found a radar box yet. I like your results. 33% on K band isn't bad for a start.

As for the horn, I love this thing - when it works. Sounds like a cross between a Cadillac and a freight train. Had a guy try to occupy my spot on the freeway in an old van with the windows down. I laid on the horn and after about 2 seconds it stopped while my thumb was still on it. Later in the ride, tried to use it and nothing. After I stopped, then turned the key back on, it worked. These bikes don't have fuses but supposedly have an ability to reset themselves after an electrical malfunction. Maybe the killer horn draws too much current, I don't really know, or actually care because this motorcycle is fast.

 

Thanks again, Bill F.

[roadscholar]

I kinda figured a real smart guy would intercept me on the horn. Good call CoDinn.

[Ken H.]

The horn is such a strong current draw that if you lay on it for too long the computer will shut off that circuit to protect the wiring.

This is an issue BMW should, and I hope is, working on. Regardless of opinion on use of horns on a bike (a different discussion) the darn thing should honk until you quit holding the button.

 

Here's a tidbit that is a piece of the puzzle though - The ZFE module will shut down the circuit if the current drain is too high or too low. I switched out the horn on our GS to an aftermarket one controlled by a relay. I removed the factory horn altogether. Initially I could only get a short blast before the ZFE would cut the circuit. I had to add 10 ohm of additional load on the circuit to get the ZFE it to keep the horn circuit on continuously.

[codinn]

Ken,

 

Good points. I'm not an electrical engineer, and I assumed that the current draw was too high for the limit specified by the computer. Mainly because it is so loud!

 

I guess I should have been more specific that the current draw was out of spec. I have a hard time believing the wiring is insufficient for the task, though that may be the case. Specifying too low of a cutoff was probably an oversight on the part of the engineers. I'll bring it up with the dealer at the 6K service.

[ScottT]

Has anyone come up with an interesting solution?

I have connected the left horn directly to the battery via a relay. The relay is controlled by the existing left horn leads. This solved the problem of the horn circuit shutting down.

[JayW]

I have read about this problem, but have not been able to reproduce it on my own R12RT. I have blasted away repeatedly for as long as I can stand it, and have never had the horn stop working. My bike was made in late June of '05, so maybe this is only a problem on earlier samples.

 

Jay

[ScottT]

I have read about this problem, but have not been able to reproduce it on my own R12RT.

I have two friends who got their RTs in June and their horns have not malfunctioned. I do think the percentage of bikes that do have a horn problem is quite low. I guess it doesn't help that an owner like me fixed it without reporting it to BMW. For me the fix I implemented was far easier than the time for convincing BMW there was a problem with the horn and then waiting for them to fix it. Now that the bike has been out about five months BMW probably knows that there is an issue with some RT horn circuits shutting down.

[CraCol]

but have not been able to reproduce it on my own R12RT. I have blasted away repeatedly for as long as I can stand it,

 

Bike running? I've found with the motor swtiched off, the horn can blast away.. if the motor is runing, then it only takes a couple of 2 second blasts of the horn to kill the circuit.. Shutting the bike off, then back on will reset what ever is killing the circuit. BMW has the dealer ordering new horns to fix the problem (I'm doubtful it will work)..

 

Craig

 

Craig

[ScottT]

Bike running? I've found with the motor swtiched off, the horn can blast away

Mine did the same thing. With the engine not running the horn blasted away with no problem. While riding it would shut off if left on for more than a half-second or so.

[JayW]

Bike running? I've found with the motor swtiched off, the horn can blast away

-----------------------------------------------------------

 

Yes, engine running and bike moving. I tried again last night on a lonely stretch of road with several long blasts one after the other, and then again in a few minutes. My horns have yet to fail me.

 

Jay

[George Brown]

This is what I "LOVE" about technology. Horns have been around for a century and once we interface them with a computer they quit working.

[dmenace]

I bought the first one delivered to our dealership.

I've layed on that horn real heavy for an extended period a couple of times....no failure whatsoever.

[James Clark]

This is what I "LOVE" about technology. Horns have been around for a century and once we interface them with a computer they quit working.

 

The bike needs an emergency backup.

 

[George Brown]

LOL

[Catbird]

I've layed on that horn real heavy for an extended period a couple of times....no failure whatsoever.

Same here.

[BereIsland]

I've layed on that horn real heavy for an extended period a couple of times....no failure whatsoever.

Same here.

 

 

I must give my one a try, but I'm frightened people might think its an air raid warning

[ScottT]

I must give my one a try, but I'm frightened people might think its an air raid warning

I like that one!