fitting a rev counter

hello everyone - i have just changed my clocks from a non rev counter to a rev counter set! every gauge is working that i had before but i need a vacuum of some sort to run the rev counter?
any ideas?

many thanks in advance

Vacuum? Are you sure it's not the economy guage? I went from a Formel E to a non MFA GTi dash and ditched the vacuum connection.

vacuums for the mfa bit, u need to run a cable of the negitive side of the coil for the rev gauge, but cant remember wha wire to on the clocks, someone told me how to do it on here a while ago and i saved it on my computer but i re formated the computer a few wks back and lost all my stuff    if u have a look through the old posts youll find it somewhere,

simon