The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: oilyrag on September 10, 2007, 05:38:37 AM
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My horn has stopped working. It works OK tested off the bike on a 12v battery. Finding one of the 2 fuses blown I thought this might be the problem, but replacing the fuse has not returned life into the horn.
Does the horn wiring go through a relay? Looking at my factory manual the wiring diagram indicates it does not.
So what where would be the most likely place to start looking for the problem?
Re earlier postings about my panniers and pannier frames... just done 600 miles to Ireland and back without any problems with the fittings, it is all still rock solid. Mind you it was only after I had started off that I noticed the horn was silent!
Thanks
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What year is it, as my '83 has a relay on the horn?
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Sorry...
I should have put that in. It's 1980 vintage.
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If you have a voltmeter, I would next test the horn switch itself - I believe that the BMWs up through 84
had the power wire going through the switch to the horn, rather than on other bikes which used the switch
to complete the ground circuit to the horn. you should see +12V on one of the leads that plugs into the horn
only when the switch /button is pressed. If you not, then I'd look for corroded contacts, broken wiring, or
(hopefully not) a broken switch as the cause of the problem.
If you have dual or non-stock horns, such as the Fiamm, it is very possible that you do have a relay to engage
the horns, as they draw alot of current and more than what should be allowed to go through the horn switch
itself. In this case, the horn button sends power to the relay coil, which closes and sends the main power
from the battery (there may often be an inline fuse in the wire harness here) to the horns. The relay, if youhave one,
is usually under the gas tank toward the rear. Do you have a digital camera that you might snap a pic ?
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Check all connections carefully to make sure they are tight and not corroded. Some horns have an adjustment on them. The aftermarket horn I got for my Royal Enfield has an adjuster on it and even though the range of adjustment is really quite large, it will only work at one spot between 1/4-1/2 turns.....Dew.
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Re silent horn:
Thanks for the input and advice. Took the seat and tank off to check all the junction boxes, cleaned them up, paying special attention to the earth points.... bingo horn now working again. Nice loud sound to it as well.
If anybody wants a wiring diagram of R65 1980 I can put a picture of it up on my website.
Regards
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How about posting it in the new R65 Technical FAQ / Procedures section, make sure you note that it is for an '80 model year, as changes were made starting with the '81 model year.
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How about posting it in the new R65 Technical FAQ / Procedures section, make sure you note that it is for an '80 model year, as changes were made starting with the '81 model year.
OK can do... but I notice one picture only, I will see if I can stitch them together and still have it readable.
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Or you can put the pictures on your website, and put in multiple links to them from the message in the
technical forum - I believe that should work.