All computers have a tach signal. Never a need to "run" a tach signal. My completely base model Contour has a V6 cluster powering a tach as we speak. Custom, yes that will work, even if it IS a V6. If it happens to be a V6, send a PM to striker or me and we can fix the situation
Zorrex you are totally missing my point. Not all cars have the tach WIRE in the cluster harness. Yes all computers have a tach signal and that is why if the wire is not in the harness you have to add it and get the signal from the computer.