the speedo signal for your car runs through the abs before it goes to the speedo head, so if you have no speedo signal that is probably your abs light on code. YOu may be right though about wiring, the wires coming from the sensor on the rear axle may be broken. i would unplug the harness and check from the sensor up to the connector on the right rear.the speedo wiring has a grey loom covering the wires, and the connector has a wire that must be removed to disconnect from the sensor. good luck.