One of my tachs is dead and the other one flops around from time to time so I figure it's just a matter of time before it's kaput. I was considering just ditching the tach and going with a big clock in that spot but I do like having an indicator of engine speed so I cooked this up:
tach2 - YouTube
That was just some testing of the LED's to get a feel for it but I finally got it nailed down using a Hall effect sensor to pick up RPM.
I was thinking about putting it (Well, a more refined version) in the PRNDL spot in the dash because it's unused in a 116 SD.
Any input? I'll probably have to dim the LED's at night or something and I was just going to trigger it off a magnet epoxied to the PS pump pulley.
I had also considered gutting the tach and putting the LED's around the outside of the dial on the hash marks and a shift light in the center but the asymmetry would probably bug me...