1993 Chevy Astro dash cluster

I pulled the dash cluster out and replaced the six larger bulbs to light up speedometer ,fuel,charging, temp- checked existing bulbs with meter and they seemed good- the turn signal indicators work,check engine light works brake warning works- general dash lights have never worked in 2 yrs i owned van is there a fuse not in place? what powers the dash cluster -i assume i have power because of turn sig. and such is there a separate power supply built in to the cluster i have gauges for temp,charging,fuel,volts but can't see mph,fuel,volts,charging at night what should i check