I purchased a 1975 R90/6 several weeks ago and just today realized that the horn does not work. I tested the leads going to the horn and did not get 12V when pressing the horn button. I opened up the headlamp enclosure to make sure it was not a blown fuse and I wasn't too happy with what I found. I see wires soldered to the exposed fuse posts. Shouldn't they be soldered to posts on the back of the circuit board? I have to go pick up the 15A fuse which corresponds to the front brake light and the horn, but I'm skeptical at how well it will sit in the posts with these wires soldered to it. I attached a photo of the fuse post. I'm comparing mine to this photo I found on another post here (http://img.tapatalk.com/d/12/10/23/dasu3y4a.jpg) I discovered or caused another issue when pulling wires back to expose the fuses, I suppose I found a short, as the head lamp and the brake/taillight turn on (key is not in). If I push on the black plastic part of the ignition, they turned back off, but when I start moving wires and cables around it goes back on. I attached a photo of the back of the ignition, including the black plastic piece. This is my first motorcycle, and I don't even know where to begin troubleshooting. I have the Haynes and Clymer manuals, but only Haynes here, and can't find any info on how to troubleshoot the latter issue.