R1200RT 2 x Stock Horns

[TJRL]

I have a 2008 R1200RT which came with a single puny "horn". Looking at a 2005 BMW R1200XX repair CD it shows 2 horns on the RT. A "rear" horn where my stock unit is and a "front" unit up front on the left hand side.

 

So I am assuming BMW will not have changed the wiring loom but just removed the second horn (to save money / weight?).

 

If this is the case can I just add a pair if twin tone horns onto the OEM wiring, or do I need to add a relay powered direct from the battery?

 

Second question, if I try the direct installation onto the OEM wiring and it does not upset the CanBus is it fair to assume the installation is OK? On the basis that if my new horns were drawing too much power the CanBus would shut down the feed.

 

Any thoughts?

 

 

[markgoodrich]

The link at the end of this note will probably tell you all you need to know about adding two horns. Before you buy two horns, double check to make certain you don't already have one of the pair. If yours is a flat disc without a "horn" mouth, you'll need both; if it's got a "horn" mouth, you almost certainly have the high tone unit, and will only need to purchase the low tone unit.

 

I don't know about the '08 models, but previous years do still have the wiring for both horns.

 

I have an occasional problem with my dual setup, in that the horns will cut out until I've restarted the bike. This happened when I had just the single horn, too.

 

Read the thread all the way to the end, to learn from all my mistakes.

 

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=196968

[gettysburg]

I have an occasional problem with my dual setup, in that the horns will cut out until I've restarted the bike. This happened when I had just the single horn, too.

 

 

That's curious, I've never had a problem with my dual horns. I've repeatedly laid on the horn for 20 secs. or more just to see if it would cut out and it never has. I didn't go with the OEM horns, I installed a set FIAMM Freeway Blasters; maybe that's the difference.

[RoadJunkie]

I have an occasional problem with my dual setup, in that the horns will cut out until I've restarted the bike. This happened when I had just the single horn, too.

 

 

That's curious, I've never had a problem with my dual horns. I've repeatedly laid on the horn for 20 secs. or more just to see if it would cut out and it never has. I didn't go with the OEM horns, I installed a set FIAMM Freeway Blasters; maybe that's the difference.

 

Same on my '06...2 horns, no waiting.

 

 

[marcopolo]

I have an occasional problem with my dual setup, in that the horns will cut out until I've restarted the bike. This happened when I had just the single horn, too.

 

 

That's curious, I've never had a problem with my dual horns. I've repeatedly laid on the horn for 20 secs. or more just to see if it would cut out and it never has. I didn't go with the OEM horns, I installed a set FIAMM Freeway Blasters; maybe that's the difference.

 

I have an '06 with the single, wimpy horn. If I lay on it, the bike will shut it down, until I "reboot" by shutting off, then restarting the bike.

[Beaky]

I fitted one after market horn Steblus Magnum (from Nippy Normans in the UK) to my GS and that is plenty loud enough so I plan on doing the same on my 08 RT. there were no canbus issues but space on the GS was a bit tight- not a problem on the RT. cost was about £8 so a lot cheaper than buying the OEM horns.

[markgoodrich]

yeah, I know, the horn cutout is intermittent. I can honk forever sometimes, and other times, it just cuts off after a couple of seconds...hmmm, seems like every time it's cut off, i've been honking at buzzards....

[Bruce H]

OK, most of this thread deals with an RT, how about the lowly GS. my horn is a weinie pancake style. (07) is there enough current to run a freeway blaster's without a canabus issue? what about finding connectors so I don't have to cut off the factory connector? i'd like to make it plug and play so it coulld be reversed if it didn't work?...

 

other GS's out there who have done this?

[Semper_Fi]

Hook up a relay to the new horn you want and use the hot wire of the orginal bike to drive the relay.

 

This way the main load is handled by the realy and the CanBus does not "see" anything abnormal

 

Summary - your control of the relay is by the regualr signal when you hit the horn button and then you run a wire directly from the battery to the relay, where once energized the battery voltage goes to the battery.

 

Get a standard car relay of 30 to 35amps, use the appropriate gauge wire to wire to the horn and you should be all set.

 

 

[chaparral]

Is there enough room to install an ooooga horn? enought current also?

[Beaky]

I wasn't so squeemish- I chopped the cable at the OE horn on the GS, fitted a couple of spade connectors and fitted the replacement horn. No relay, no canbus issues, everything worked as before except the horn gave a real blast. There isn't a lot of space on the GS but the Stebel Magnum just fitted.

[TJRL]

Thanks for all the advice, I have now fitted two "full volume" horns to the OEM wiring and they work well without any issues. The longest test blast so far is 15 seconds, all seemed OK the wiring did not get warm, CanBus did not shut down, etc.

 

So thanks again for all the help.