I have just aquired a Lucas rev counter. on the back are 3 terminals marked + - and G. I can guess what to do with + and - but I am not so sure about G.

on the side there are the following marks:
333/230/105/25

12V/233Hz 4Zyl/ 4 Takt
Masse Frei 12.89

I can guess the 12V and 4 Zyl I don't know what the 233Hz refres to . Full scale goes to 7,000RPM

Any ideas folks?

TIA

Caber

7000revs/min * 2 sparks per rev = 14000 cycles/min = 233.3 per sec = 233Hz

Hi,are you sure G is not IG for ignition?
This wil take a feed from the ignition pulse,depending on your type of engine or ecu where it takes the signal from.

[Edited on 21/11/05 by DEAN C.]

ive fitted a very similar lucas rev counter to a morris minor, i can check how i wired up the three terminals if u like...