Hello All I've been having an intermittent fault with my horn since a few weeks ago. It wasn't sounding so I gave the horn a tap with the back of a screw driver and it was ok(ish) for a while. The sound from the horn was "croaky". It then just failed. I ordered a new horn and it also showed the same symptoms. I've checked the following: - Both horns work when a 12V is applied to them. - Continuity of : - Black Blue wire from Horn to Righthand switch cube (OK) - Purple Black from Horn switch to Horn (OK) - Black wire to ground (I get one bleep and then nothing on the multimeter) I'm probably showing my naivety on this last test Could anyone please let me know if this is a valid test and whether anyone has faced anything similar. My next test is to run a wire from the negative terminal to the horn directly. Finally, where does this horn ground actually ground to Thank you in advance (You can probably tell I'm not much of an electrician) Cheers
If there are two terminals to your horn, one will be live & one earth (negative). On the earlier bikes, there is a permanent live and the horn button connects the earth when applied. Hth.
Same as the early ones then. Make sure the rear brake light is working. So, you disconnect the negative spade connector from the horn (Black/Purple wire in above diagram) Then take a piece of wire attach it to the now empty horn lug that you took the spade connector from. Then touch the other end to any bare metal part of the engine ( eg casing screw) or the negative terminal of the battery. If the horn sounds when you touch earth, then the horn button or (more probably) the wiring between it and the horn itself has a fault.
Yes brake light works The horn sounded with this test So I tested voltage from the black/purple wire to ground (negative terminal too) - No ignition and no horn press = 0V - Ignition on and no horn press = 3.5V - Ignition on and horn pressed = 28.5V (also saw 36.6+V too) Black/Blue wire: - No ignition and no horn press = 0V - Ignition on and no horn press = 12V - Ignition on and horn pressed = 12V I'm sorry for what seems like being spoon fed but I am not sure how to proceed with the information that I have. The 28+V on the black/purple wire seems odd, from a lay perspective and is there meant to be any voltage on this wire with no horn press? Thank you so much for your time and effort in replying and helping, as always much appreciated.
Because the horn sounded when you connected the negative terminal to ground, then that pretty solidly points at either the horn button itself not making a good connection ( possible but rather unlikely imho) or (most probably) there is a break in continuity of the wire itself, somewhere between the button & the horn connection. I feel you do not need to use the voltage test scale on your multimeter, as you have already confirmed that there is a live supply to it. Perhaps use the continuity option (or ohms resistance) to try to locate where the brake in the circuit is located ?
Evening All So, it's been a hectic few months with my sons wedding and work. I just had another look at this horn issue I've been struggling with. Two points to note: - I've determined that the Purple/Black wire from the horm to the connector block is the problem - the earth wire from the block is shown in the serive manual to be pin 8, but mine is wired to pin 6 and the purple/black wire from the horn is shown in the manual to be at pin 6 but it's actually in pin 8 (not that it matters but just an FYI) Now, how do I depin the wire (purple black in my case) from the connector block? I might end up just running this wire outside of the block for now. But any advice on how to do this neatly would be apprecaited. As always, thank you very much for your time and effort in helping. Cheers
Congrat's on the new Daughter in Law.. Fwiw I have dismantled the other side of the plug (when I configured my D675 to have an ON/OFF light switch), but not the socket side that is attached to the loom. I would expect that the socket side will insert from the loom side, and will have a sprung plate to the rear of that "box socket" shown in your image. When the box socket is inserted into the rear of the plastic housing the sprung plate will prevent the socket from being pushed back out when the plug and socket are connected. Perhaps you will be able to figure out a way to release the metal box socket by inserting something pin like down the side of it ???
Hi All I have to report that I am still struggling to get this horn sorted, as it took a back seat to life, with work and lots of other things going on. A few months ago did a tour of Morocco on a BMW F750 GS, 2,000Km of riding in the Atlas Mountains and down to the edge of the Sahara got me my riding fix! Here is a question that I hope you can help me with. When I depress the horn switch the front position light and rear light dim and the horn tries to sound but doesn't. I've check the resistance from the connection block (Yellow wire) from the front to the block at the rear light. All seems to be in spec, no inidication of any breaks or increased resistance. I really don't know what further tests to do and how to fix this issue. The last resort might be to run a new live directly from the battery and use the ignition live (Yellow) to trigger a new relay for the horn. When I connect a live from the horn to the battery, leaving the ground from the switch untouched, this does fire the horn ok. Whilst I have a few strands of hair left please send me your suggestion (not about hair transplants!!!)
What I did do to check the ground connection was run a new wire from the battery to the horn directly, so when the horn switch is depresssed it completes the circuit to ground and the horn does sound. Is that a valid test for checking a "poor earth connection"?
Silly question, but did you have a look at the pushbutton itself on the handlebars? I too had a problem with my horn working intermittently and making croaky noises. I also bought a new horn that didn't fix the issue! I tried removing the block with the pushbutton from the bars and spraying contact cleaner and GT85 in there... After a few pushes of the button the horn started working and has been fine since then.... worth a try?
Hi Wobble King Not a silly question at all. One of my first steps was to check: check the horn to check it wasn't just guncked up and stuck fuses and relays all good battery fully charged tested ground to make sure that was ok switch, pulled apart, used emery paper to clean the contacts and as you suggest, contact cleaner sprayed etc. For some reason I think that there must be a bad connection in the loom somewhere, causing the live yellow line (backbone - energised on ignition) not able to provide enough current, not sure how to test this. Really appreciate the help and suggestions.
