No speedo on 02 Galant

I replaced the factory stereo in my 2002 Galant with an aftermarket radio. Immediately,my speedo and odometer quit working. I think there is either a voltage or a ground provided by the radio that is taken out of the loop when you replace the radio. I'm trying to locate the VSS and speeodometer wiring diagrams to see how they tie in with the radio. Ironically, I upgraded the stereo even more and had to run 4 guage wire to the amps. Disconnected the battery which cleared my OBD memory and now I can't pass emissions. It appears that the OBD clears itself whenever the battery is disconnected and resets itself after 100 miles have been driven. Sad part is the car is too stupid to know it has gone 100 miles without the odometer working. Maybe the stereo upgrade wasn't worth it after all.