86 Coupe GT digital dash

[Kevin Kraus <krausk@gwis2.circ.gwu.edu>]

I just got my car back from the repair shop, where they were 
checking out the rear tailight cluster (itself a consistent problem)
As I was driving to teach, I noticed that I was only looking at the
speedo, odo and clock lit up.  all else was black.
NOW, it all lights up momentarily when I start the engine, but what is the 
problem with it not reading while I drive?

Thanks for your interest, Kevin