2000 Ford F-350 7.3 diesel

OK I'm on road today at a red light and my truck just died. When I first got the truck I read that the cam position sensor can just stop anytime so I changed it The truck had 173000 now 184000. The article also said that if you crank it and the tach doesn't move its a good indication that the Cam P Sen is bad. So I purchased a new one put it in and nothing. When I turned the key on I noticed that the wait to start light doesn't come on now and the tach doesn't appear to try to move. So I checked all fuses inside and out under the hood.I found a relay for the PCM and changed it with the blower relay nothing. I purchased a diagnostics unit($280.00) from Auto Zone and hooked it up and it says it can't make contact with the PCM Checked the pins on the trucks connector according to instructions in the diagnostics manual. Pulled batteries and had them checked and there good PLEASE HELP STILL ON THE SIDE OF THE ROAD! Think its my PCM? If so how do I know for sure?