The dash illumination dimmer switch is shut off or broken.
About the only thing they have in common is the headlight switch. Have it checked out.
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NO , Not from the factory.
Assuming you have already checked the bulbs and sockets, next check the fuse, then check the brake light switch, then check the signal switch.
Have you checked it's starter?
You left some wires unplugged.
It is usually wired in with the radio or the courtesy/dome lights.
its the tail light fuse
have you checked the fuel gauge itself to make sure it is working
Probably because the circuit board for the bulbs is rusted out at the bottom
Be sure that the dash light dimmer control is not turned off and check the fuses.
1989 chevy 5.7