Assuming it's a VDO cluster I had a little russle through my collection and found a 'bare' tacho.
Attached are some pics which may or may not assist. Quite frankly I cannot now recall what the hell my writing on the tags mean!
Without digging deep into my precise wiring files I think that the tacho may just have one spade connector (single Lucar wire (colour?) which always gets missed on re-connecting?) which can go to either of the two visible spades on the white backboard above the tacho fitting .... but 'hey ho' who knows without further deep thought!!
Bob
