Had the same problem with my 85gt as do all owners of fieros with the Non-backlit gauges.
The January 2000 GTA Fiero Club Newsletter had an article by Justin Cohen:
"Non Backlit Dash Modification-Brighter Dash"
The stock bulbs are # 194 with a 3 watt output
Remove the # 194's and replace with # 168 they have the same configuration and are 5 watt output.
I went to CTC and bought a handfull of # 168's and changed them out, also cleaned the glass as recommended. I forget how many bulbs it took. I bought ten the first time arround and was so impressed I went back for more. The old bulbs can be used to replace the ashtray lights, both mine were burned out.
WOW! what a difference, I can see the instruments. Almost five years later and I have never blown a fuse so the circuit can handle the extra load.