Horn wont work, kinda unique problem SOLVED

One issue to store away in your memory banks. Horns that won't work, have seen this issue. A horns tone can be adjusted by a small screw on the back of the horn. I have had a couple of cases where that adjusting screw is frozen to the inner diaphragm, so that the diaphragm won't vibrate and produce a sound. The solution is to simply rotate the adjuster screw back and forth a 1/4 turn to free it up.