Come to find out on my dakota same everything as yours....my cab mounts were bad and was allowing my cab to rest on the wiring harness and was shorting everything out....first truck shuts off...gauges went crazy....then brake lights, running lights, blinkers would work then not work...put new cab mounts in....(using old hockey pucks)....fixed the wiring and whala no more issues.

 

Something else to check out, before I pull apart the potting in the pcm and check the board,

 

Checked out the cab wiring harness and found it to be ok. Pcm here I go.

 

Replacement Pcm seems to be the answer, I have run the truck for a couple of hours, on three occasions
So far so good, filled the tires and the brakes were not locked up, this was sitting a long time, drove to the corner and back, still in testing mode for me, when I can trust the Dakota I will drive it more.

Thank you for your time and effort to help me, I bought the lifetime warranty on the PCM.