hey man.. sorry about these guys im a noob also and iv gotten shit for not searching alot too. but it is true i realized that after i started using the search tool.. but it still no reson for everyone to be an asshole.. sorry
but yea what kind of tach is it?? when they are new you will have to cut certian wires to indicate what its bein installed on
like on my auto meter ther was three wires and one you cut if you were installing on a v8,one for 4 cyl and i think one for rotary so yea if its new just read the installation directions