The Execlamation point usually means TROUBLE (not specified) if you have a code reader, plug it in and read it. It will tell you something.
Of course.. I know OBD 1 better than OBD II.. On OBD 1 when you plugged in the reader you always got one code (I think 888) the code translates as "no signal from ignition pulse sensor" or some such in formal technical language.
In simpler English: "Engine not running".
They coded it 888 because that way you tested the segments on the 7 segment displays.