I did my digital dash conversion and everything is working except for two things.

The speedometer does not register the speed your going it stays at zero. I changed the buffer out to see if that was the problem and it did nothing..im thinking of the speed sensor from the transmission isnt compatible with the unit.

second my odometer registers nothing that whole part has gone totally blank..or should i say has always beeen that way..i cracked that screen a while ago and recently replaced the LCD screen.. but before that it registered nothing not even the fuel economy ect..

im using my original computer.. I have a feeling that may be the problem.. the 1988 donor car didnt have the computer anymore and i didnt take the engine harness which i think i should of done, because i noticed that there are two terminal connectors over by the computer that are apart of the dash harness that connect to the engine harness over where the computer is. i noticed the 1988 dash harness has a few wires in the terminal that the 1990 TPI engine harness does not have..Should i also go and get the 1988 engine harness??...i think that engine harness was mass air..i dont remember..any help would e greatly appreciated..thanks