If the OD still doesn`t work. You get hook both the black wires out of the transmission to a toggle switch that runs to ground. When the switch is flicked.. it grounds the wires and you have OD. Once will have 12 volts and 2 are for ground.

My OD didn`t work because the speedo didn`t work. The speed sensor is in the speedo. Once I fixed the speedo, the OD worked.