I'm fitting an Escort rev counter but don't know which is the live terminal and which is the tacho impulse.
There are only two choices, but if I choose the wrong one, will it damage it?

Or is there a way to tell which is which from looking inside it?

David

I worked out the wiring on mine from the original dash connections and internal configaration of the tacho, but am pretty sure you wont do any damage by swapping the live and coil connections as long as you know the correct earth terminal.
Paul