Richard,
The AOD has a throttle-valve lever that operates a shaft inside the shifter lever on the transmission. You should adjust the cable so that it pulls the TV lever fully at full throttle on the carbureter. There should be no free play on the TV cable at idle. If you adjust the idle more than 50 rpms then you should readjust the TV. The official way to adjust the TV pressure is with a gauge from the 1/8" npt test port on the side of the tranny. That three wire connector should be a four wire connector and only activates the neutral safety feature and the backup lights.