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Discussion Starter · #1 ·
My F650 has always been well cared for and garaged, so I've been very lucky over the years with a trouble free Beemer. However the MOT is due next month and I have a problem with the horn - it simply stopped working! I've had the horn off (what a job that was) and tested on the bench with my battery and multi meter and the horn works. So the problem is further up, perhpas an earth fault somewhere? Any thoughts ideas greatly appreciated. I don't mind removing the panels etc but don't want to be struggling with other parts. Anybody know the route the horn cables take please?
Thanks
Clive
Inverness.
 

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My one stopped working too and it was a break in the wiring where the horn wires exit the loom near the head stock. Easy enough to check with a volt meter by pushing a safety pin or other sharp probe through the wire insulation, working your way back until you find some power, and cut and splice a new bit in.
 

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Check that the earth wire to the horn has a good earth connection. Put then check that the 12 volt positive side has power getting to it.
If the earth is good, a nice low or zero ohms reading to the frame.
Then have a look at the horn button. Could be a wire off, but check that power is getting to the horn button and if power is at the output side of the button when it is pushed.
Good luck
Pete
 

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Discussion Starter · #4 ·
My one stopped working too and it was a break in the wiring where the horn wires exit the loom near the head stock. Easy enough to check with a volt meter by pushing a safety pin or other sharp probe through the wire insulation, working your way back until you find some power, and cut and splice a new bit in.
Check that the earth wire to the horn has a good earth connection. Put then check that the 12 volt positive side has power getting to it.
If the earth is good, a nice low or zero ohms reading to the frame.
Then have a look at the horn button. Could be a wire off, but check that power is getting to the horn button and if power is at the output side of the button when it is pushed.
Good luck
Pete
Thanks guys, all very helpful ideas. Yes, I've already checked the horn switch - always start with the easy stuff! - And as suspected the wiring and switch work perfectly at the 'bar end of things. I also know the horn is good, so it looks like a day in the garage tracing an electrical fault with my trusty meter. I'll start looking as per your suggestions, seems this is quite a common problem on these bikes judging from earlier posts.

Will let you know how things progress.
Clive
Inverness.
 

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Thanks guys, all very helpful ideas. Yes, I've already checked the horn switch - always start with the easy stuff! - And as suspected the wiring and switch work perfectly at the 'bar end of things. I also know the horn is good, so it looks like a day in the garage tracing an electrical fault with my trusty meter. I'll start looking as per your suggestions, seems this is quite a common problem on these bikes judging from earlier posts.

Will let you know how things progress.
Clive
Inverness.
Sorry if missed this, what year/model is it ?
 

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Finding broken wires can be tricky. My first place to look is where they exit the switches or device they are connected to. Vibration and movement tend to create havoc with wiring that is fixed at one end and floating on the other.
Then grab the wire and stretch it.( I had a broken wire on my 12 volt socket last week. I grabbed the wire pulled on it and it came apart. Then just dug into the loom where the other end was and connected a new wire to the socket)/
If you can't find the fault easily, I would just run a new wire from the switch to the horn and be done with it.
Good luck
Pete
 
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