Horn problem during conversion of a 2009 R1200RT-P

[Jean Dufresne]

Greetings from Montréal,

 

I am new to your forum and hoping to get an answer to my little problem with the conversion of a beautiful 2009 R1200 RTP to civilian configuration. With the help of my friend Ben, we succeeded in removing the police pack switches from the handlebar and are now ready to reassemble the motorcycle (there is parts everywhere in the house...). We checked every time we remove or unplugged a switch to be certain it didn't cause any electrical problem. We had to detach the FIAMM horn which was replacing the original horn from the circuits and now would like to re-install it without using the police pack wiring. Here is the problem: the horn switch doesn't activate the new relay (!), in fact, there is no continuity when it is activated and checked with an Ohm meter. The horn switch was working fine before. We checked the circuit diagram from Clymer reference book but it doesn't give an explanation or suggestion. Is there anyone who can help us?

 

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[dirtrider]

1 hour ago, Jean Dufresne said:

Greetings from Montréal,

 

I am new to your forum and hoping to get an answer to my little problem with the conversion of a beautiful 2009 R1200 RTP to civilian configuration. With the help of my friend Ben, we succeeded in removing the police pack switches from the handlebar and are now ready to reassemble the motorcycle (there is parts everywhere in the house...). We checked every time we remove or unplugged a switch to be certain it didn't cause any electrical problem. We had to detach the FIAMM horn which was replacing the original horn from the circuits and now would like to re-install it without using the police pack wiring. Here is the problem: the horn switch doesn't activate the new relay (!), in fact, there is no continuity when it is activated and checked with an Ohm meter. The horn switch was working fine before. We checked the circuit diagram from Clymer reference book but it doesn't give an explanation or suggestion. Is there anyone who can help us?

 

Afternoon Jean

 

It is a fairly simple horn system on the 1200 hexhead that can be a  real pain to troubleshoot as the horn is computer controlled (ZFE module) with no external horn relay. 

 

So let's start with the wires running from the ZFE module to the horns (there are 2 separate  horn wires). 

 

One horn pig tail uses a green/gray 12v supply wire with a brown low (ground)  & the other horn uses a green/black 12v supply wire with a brown low (ground). A stock 1200 civilian 1200RT only uses one of those horn wire pigtails.

 

Witch one are you using?

 

So start by verifying that the brown wire on the horn pigtail that you are using actually has continuity to ground.

 

If the brown wire has continuity to ground then you next need to verify the green/gray or green/black  wire is intact all the way back to the ZFE module. 

 

If all OK per above then your problem is either inside the ZFE module, or in the handlebar switch assembly, or you have an  open the wiring between the handlebar switch & the ZFE module. 

 

You might try plugging the horn into the pig tail connector as the ZFE monitors the current as  there is no fuse in the horn circuit. (it's possible that your test light or voltmeter doesn't provide enough load to allow the ZFE to see it (longshot but should be eliminated).

 

The handlebar horn switch is a N/O switch that goes closed when you push the horn button the wire colors coming out of the horn switch are  brown/black & brown/yellow. So you might also check that the horn switch is closing those 2 wires (check both at the horn handlebar switch connector & re-check at the ZFE module.   

 

[Jean Dufresne]

Thank you very much Dirtrider,

 

I am not close to the motorcycle right now but I remember that the connection of the FIAMM horn was using the brown/yellow and the brown/black coming from the left handlebar switch block. Partially removing the wiring protection we could see a white wire that seems to connect those two wires. ( I am using the Clymer manual M510, page 16-20). Conduction is good from each point of connection to the connector (unplug from the central electronic unit) but there is no continuity at the switch between the Brown/yellow and the brown/black wires when the switch is depress so I suspect it could be the switch. Also, there was a fuse of 10 amps (in the location where a 7,5 should have been) that was blown  and replace by a 10 amps. I suspect this has to do with the horn circuits although I couldn't find a diagram showing the circuits relative to the fuses... I will probably keep the secondary battery located in the glove compartment and use it for the double horn I would like to install.  Next I am thinking of disassembling the handlebar switch to check the horn switch hoping it is a simple on/off switch. I should do that this weekend when I am back in town. I have all winter to figure this out (it is snowing here :-). 

 

I already spent 2 days trying to figure out this problem that should be so simple to resolve so your comments are really appreciated. 

 

Merci!

[dirtrider]

37 minutes ago, Jean Dufresne said:

Thank you very much Dirtrider,

 

I am not close to the motorcycle right now but I remember that the connection of the FIAMM horn was using the brown/yellow and the brown/black coming from the left handlebar switch block. Partially removing the wiring protection we could see a white wire that seems to connect those two wires. ( I am using the Clymer manual M510, page 16-20). Conduction is good from each point of connection to the connector (unplug from the central electronic unit) but there is no continuity at the switch between the Brown/yellow and the brown/black wires when the switch is depress so I suspect it could be the switch. Also, there was a fuse of 10 amps (in the location where a 7,5 should have been) that was blown  and replace by a 10 amps. I suspect this has to do with the horn circuits although I couldn't find a diagram showing the circuits relative to the fuses... I will probably keep the secondary battery located in the glove compartment and use it for the double horn I would like to install.  Next I am thinking of disassembling the handlebar switch to check the horn switch hoping it is a simple on/off switch. I should do that this weekend when I am back in town. I have all winter to figure this out (it is snowing here :-). 

 

I already spent 2 days trying to figure out this problem that should be so simple to resolve so your comments are really appreciated. 

 

Merci!

Afternoon Jean

 

There is no fuse used in the BMW stock  horn circuit, the  horn circuit is protected with a crowbar type circuit inside the ZFE (central electronic) module. 

 

You could easily have a bad horn switch (there were a few issues with those).

 

Just unplug the handlebar switch pod, then connect an ohmmeter between the brown/yellow and the brown/black wires coming out of the switch, then push the button. The ohmmeter should should show the switch going from open to closed as you push the horn button. 

 

That white wire is the "high" going into the actual horn switch itself, it's tee'd  into the  brown/black wire that goes to the high beam & the flash to pass switch. (that brown/black wire into the handlebar switch is  used for more than just the horn "high" feed).

[quanttrom]

Hello Jean,

I hope you were able to fix your horn issue. I just spend a good amount of time going over my 2011 R1200RT-P police wiring harness and I can hopefully help. I think the 2009 are different.

 

The 2011 police wiring harness taps into the horn connector at the front and a wire leads to the back. I assume you and your friend removed that tap and reconnected the horn?

 

If you get a chance, have a look at the Police Motorcycle Wiring Harness Information here and it will give you an idea of what was tapped and modified on police vehicles.  www.bmwmc.net

 

[Jean Dufresne]

Thank you Quanttrom,

 

Sorry for the delay in my reply , I am just back in Montréal from spending some quiet time in the country. I appreciated your suggestion. The site you proposed is helpful in my search for a solution to the horn problem I face. I think I isolated the problem to the switch itself now and just removed it from the motorcycle. I will disassemble it to check the switch. I will keep you posted of the result.

 

Take care!

 

Jean