The tach on my 1968 E-Type stopped working. I called a local speedometer repair shop who wanted $250 to repair it without even knowing what the problem was (dirty contact, burnt capacitor or coil, etc.).
I then turned to the internet and learned a couple of things.
1) The Smiths Tach is intended to work with a distributor that uses points and will probably not work on an electronic ignition (i.e.: pertronix or the big electronic ignition box). The Smiths Tach is a RVI and an electronic ignition will need a RVC Tach.
2) I found a web site www.spiyda.com. I clicked on Tachometer at the top of the page, purchased their solid state upgrade and installed it in my Smiths tach in about 20 minutes for about $50. They even sent a miniature screw driver and a cable to connect my tach to my computer and calibrate my tach before reinstalling the unit in my car. Now my tach will operate on a points or an electronic ignition. They even have 4-5 videos you can watch to see them upgrading Smiths Tachs (easy if you know how to solder an electrical joint). I even used their suggested wiring diagram to power my tach directly from the fuse box so as to avoid interference.
Just so you know, I have absolutely nothing to do with the vendor but I like having everything on my car working correctly; and I'm thinking you would as well.
Please be sure to confirm all information contained in this message, then proceed at your own risk.
Submitted by Wheeloz on Mon, 01/13/2020 - 22:15
Will check that out