RPM's Please
 

So I've got myself a 1996 Grand Marquis, she's absolutely beautiful, but as I'm sure many of you know there is no tachometer. Well, I know where to get a tach, but I've searched the web for the last few days and haven't found out how to hook it up. It's the 4.6, so there are coil packs, so it measures the RPM's, but I just can't find out where to hook the thing up. Do I need a tach adaptor to hook it up or is there a plug-in that I'm missing?