My rimblow wheel horn stopped working a few months ago. It worked intermittently before that. If the temp stayed below 75 degrees or so, it worked, above 75 it didn't. Kinda strange. Anyway, I found out this weekend if I turn the wheel 45 degrees or so either way, the horn works. I'm assuming there is some sort of contacts in there that must be dirty or broken. What do I need to do to fix this?