mk1-forum.net

Hi. I have an old Smiths 80mm rev counter (think it came off a Lotus) and ithas the code RVI 1003/00.
Questions:
1)How can I tell if it is meant for a positive or negative earth car? I think positive as it has a plastic block on the reverse with a wire looped through it..
2) How do i wire it up. It has a bank of 3 terminals, one of which is a red plastic twirly thing (technical term) and the other two habe brass nuts on them. In addition there is the plastic block with loop of wire I mentioned.
Many thanks. Mark

Also can I use this set up with \Metro electronic ignition? Cheers

Have a look here:-
http://mk1-performance-conversions.co.u ... trical.htm

Thanks Bob. I had already looked at this but I don't understand the bit about Impulse lead and where to put it. Which coil terminal does the black marker side go to (+ve or -ve?)and where does the other end attach to? Cheers. Mark

Not sure if you looked in the 'care of instruments' section as there is a better wiring diagram there. From memory these tachos don't like electronic ignition.

If you connect your tacho to electronic ignition it will

blow up.

i've got an impulse tach hooked up to the petrozix points replacement and it's working fine.
it is how-ever just an "hall-effect" switch, which means that it is "fancy" points.

i wouldn't connect it to any other electronic ignition system, cause you will Kill it.