Mike, I totally dis-assembled my horns a few weeks ago, to try a figure out why they were intermittent and at a reduced volume. I found all kinds of gunk inside the noise producing end of the horns. Cleaned everything up, re-assembled, and was good to go. Put on a set of ear protection and tune with the little Allen head screws. My intermittent operation problem was caused by a break in the wire, just under the steering wheel, one strand was all that was left on the wire. My son and I dis-assembled the steering wheel switch and pulled the wire out through the steering box. I had to solder a short piece of wire to the button end, then spliced it to the long end with a sta-kon butt crimp. We then slid a piece of shrink tubing over the butt splice, and shrunk in place. I've heard so horror stories about people not being able to get the wire back up the steering column, however a piece a stiff wire solved that problem, as we were able to "fish" the wire right back up. Hope this helps and you find your spring, we went at this real blind, as we didn't even break the TM out.
As I re-read this I thought I might clear something up. If you need to fix your steering column wire, pull the wire out as you probably won't have room to do the splice addition. Splice a short piece on, then pull the wire back up the column. Now you can attatch the button piece from the driver's seat and re-assemble. The button piece will
not fit through the steering column. Don't ask me how I know this.
Good Luck!