I have a 95 6.5 diesel, we recently relpaced the pmd and added the 6 foot extension cable. The truck doesn't die like it did but still does every now and then. The water in fuel light comes on and off. We had the codes read and its showing codes 17,18,31,33 and 54. When you start it up, it will run rough then you can shut it off and turn it back on and it runs fine. WE have replaced fuel and fuel filter. Could it be the main wiring harness? Any ideas?