Hey there man. Sorry to hear about your problem and unfortunately electrical is not what I'm good at lol but as suggested below, best place to post your question is in the 3rd gen electrical where more of our technical people hang out and they should be able to help, good luck!
I am just grasping at things here with your gauges. Have you looked in the 3rd Gen Electrical Section. Did you contact the company you got the refurb'd PCM from. Sorry I am not a truck expert just enjoy having mine. I will do some more searching!
Look forward to seeing you around the forum, drop me a message if there is anything I can help with.
If you haven't already please stop by the newbie section found here and introduce yourself.
Show off pics of your Ram in the gallery! The how to's can be found here!
Welcome to the Z!