I have a 2002 Cavalier that was not equipped with a tach from the factory. I would like to install an aftermarket tach but can't locate a tach lead for this. I have tried the purple wire from the wire loom that runs over the engine: no-go

Does anyone have any experience with an install of this nature. I'm under the impression I may need a tach adapter due to multiple coils but am not sure.

Dave