1996 Ford Escort Tachometer Problem

I installed an Autometer Autogage in my automatic 1996 Ford Escort 1.9SEFI. For some reason it only reads at half what it should be. For example, when I slam on the gas it shows it shifting at 2 1/2 when it should be shifting around 5k. I took a picture of the tach while i was driving. Any help on correcting this problem or if someone knows the correct way to hook it up, it would be greatly appreciated.
http://home.comcast.net/~rustler129/tach.jpg