If it runs in reverse then the problem is the main wiring loom that runs beside the engine. When you shift to Drive the engine torques putting tension on the loom causing a short. When you put it in reverse there is no tension on the loom and it runs fine. With the engine running and the trans in reverse grab the wiring loom and move the loom around (don't be shy). If the engine sputters or dies while in reverse then you have your culprit.
Open the loom by cutting the heat wrap and you will find some fried wires that you can resplice. Rewrap the loom with some heat wrap tape and drive for another 100k.
Open the loom by cutting the heat wrap and you will find some fried wires that you can resplice. Rewrap the loom with some heat wrap tape and drive for another 100k.