Diamante 2001 dies

My Diamante 2001 dies. This has happened twice. The car just dies. It's as if I have turned the car off. The key less entry works, the glove compartment light works, but all other electrical systems are off. Tooks the car to the dealer and he kept it for 3 days. He said there was a short in main harness B77 pin 6. The car died again after two months. I've taken it to the dealer again. I feel it will do this again. Any help would be greatly appreciated. :confused: