I installed a set of Hella bar-end turn signals and decided to wire the horn up there. After I finished, turn signals worked, horn didn't. After spending an hour tracing my wires I realized it was the horn itself. Wouldn't work when directly wired to the batt, had no continuity across the contacts.
I took the horn apart and cleaned up the contacts. Inside had a lot of corrosion and the membrane was torn. Put it back together (I think the right way...) and now had continuity. Wired it up and now it sounds like this:
https://www.youtube.com/watch?v=qEmEVsd ... e=youtu.be
It's basically a little ping whenever I release the button, which I presume is the electromagnet releasing. But, no actual horn sound.
Any idea what might be up? Would the torn membrane be the issue? I figured it would at least buzz. Is there a diagram of this horn available anywhere? I searched around but couldn't find much.
Thanks in advance!
It's really a simple circuit. When one side of the horn is ground (via the horn button), current flows and causes the electro magnet to energize. That pulls on a connection to the diaphragm and then the points open, stopping current flow. The spring in the system pushes it back so the points close. The process repeats over and over. It is the pull and release of the diaphragm that causes the sound. You should chase this circuit.
The points need to be clean. Also, isn't there an adjustment screw on the back? This should be experimented to find the best position for sound.
'78 R100/7 '69 R69S '52 R25/2
88' R100RS - 06' K12R
@Kurt no, there's still no sound when connected directly to the battery. Does polarity matter? The terminals aren't labeled, that I saw.
It does not matter what side gets power as long as the other side gets grounded by the horn button
54 R51/3 55 R50/Velorex 560 sidecar 64 R27 68 R69US
If there are two screws on the case, one holds one end of the point bar and the other spring loaded screw goes to the other end of the points bar. There is a pusher from the diaphragm to the contact point below the point bar.
For the horn to sound the points need to be closed at rest. After the points are cleaned the resistance at the contacts should be small. If the circuit is open the pusher is down too far. Screw out the sprung screw until the resistance comes back. Check continuity between the inside of the horn and the outside connections. Rig a battery with leads and a switch. Polarity doesn't matter. Hook up the leads. If you get a toot adjust the sprung screw for loudest sound. Put the horn back together. Check it again for the loudest sound. Play with the sprung screw to get a feel for how the adjustments work. When the horn is mounted the adjustment may be different.