My tach decided not to work today. It just went to zero and stayed there. The car is running fine. I have the Honda Service manual but this thing sucks. Why did they not put an index in this book? Anyway I have searched this book to see what the trouble shooting would be fore the tach but can not find anything. Does anyone know what I should do to try to find out why this is happening? I have checked all the fuses and they are all fine. The tach did however work for about 10 secs tonight then back to zero. Any help would be appreciated.