Digi dash repair

First of all I have an 86 digi dash that's having some issues. First off the message center doesn't work... Where does the pins go on the dash? It has a lots of different places on the one the one connector but where should it go? And then there is a little board on the outside of the dash that plugs into the harness with a stereo like plug? The little battery like things soldered on there has actually burnt the board under them... What does this do? Then my dash buttons dont work are they the same as the travveler have te same ones? I'm going to buy some for the traveler but need to know If I need them for the dash too! Then where is the mileage chip... What does that little switch on the back
Do and why doesn't my tach work? There's no lights on it so photos of a good board and Pinout diagrams would be nice too!!