According to the Ford service manual, the tach wire is a TAN wire with a YELLOW stripe. The ground is a BLACK wire with a WHITE stripe.
Power comes from a common trace on the printed circuit board that is fed by a RED wire with YELLOW stripe. Also according to the manual, there are only 3 wires to the tach connection. This is for a FACTORY tach, BTW. For aftermarket, you can just tap into the distributor side of the coil for the ignition signal.
Monday, June 29th, 2009 AT 4:01 PM