Fitting a rev counter

[GreaseNipple]

I need help fitting a smiths rev counter its my dads old one and has no wires on it. It is also positive negative earth swithabl, am i right in thinking minis are negative? If anyone can help with the wires i.e. what goes where I'd be more than grateful, cheers

[vrooom]

If ur mini is newer it should have wires already. u just plug it in. one is spade and other is round.

but then i never worked with smith rev counter.

jay

[Cooperman]

There seem to be two sorts of connection for Smiths tachos, even though they look the same.
The first, which I think is the older type, connects as part of the ignition circuit. One connection goes to the switch side of the coil (12V coil, that is) and this would be the +ve, and the other goes to the LT terminal on the distributor. In other words it replaces the coil to dizzy lead. The problem with this used to be that if the tacho developed a fault you lost your ignition circuit as well. We used to fit a by-pass connection with a dashboard switch, just in case, on our rally cars.
The current Smiths tachos, of which I have one in my '64 rally car, is wired as an addition to the ignition circuit. The positive lead is attached to the SW side of the coil as an additional connection and the other tacho lead (-ve) is the earth.
You really need an auto wiring specialist to help with this. I don't know where you live, but an old friend of mine runs 'Classic Wiring Services' in the Lake District. His name is John Vipond and he's THE expert on this. No is 01524 824313.
I hope this helps and I'm sorry I can't actually tell you how to do it.

Peter

[GreaseNipple]

Cheers for the help guys, its all appreciated. I was worried about bodging the wiring, my mini doesnt need anymore help in being unreliable, im in Hertfordshire, Ill ask the bloke that usually works on it..

[Cooperman1]

Hey, GreaseNipple, I'm in Herts as well as I work in Hitchin and live just over the border in Beds.
Email me if I can help any further.

Peter