Check the fuse first, then the switch. If this is an early model Chevy Silverado (1988-1994) these are famous for having bad light switches. If this is a post 1996 model, you may have anything from a bad ground to a faulty body control module. Another thing to look at is if someone did trailer wiring recently, this could have caused a problem with both circuits. The tail lights, side markers, parking lights and dashlights are on one circuit, while the stop lamps or most likely on another one. They will most likely have a ground in common.
Brake lights and turn signals are on a separate circuit from the tail lights. Tail lights are on the same circuit with the dashboard lights. If the dashboard lights aren't working either, check the fuse. If they ARE working, check the headlight switch.
If all the dash lights are out then there is two causes for this. The first is all the fuses have blown the other is the relay for the dashboard lights has went out.
Acura dashboard light don't work
Fix them! JTK
94 mercury grand marque dashboard, hazard, and tail lights do not work?
Check to see if parking lights are working - usually same fuse or could be light switch itself if all fuses are good
Honda dashboard lights are powered by a single fuse. The taillight fuse keeps the dashboard, taillights and hazard lights safe. If any of this units cause a short all of the components will not work.
Do you have lots of paper or other debris/refuse on the dashboard?
If the Ford Galaxy dashboard lights don't work, there could be a problem with the fuses. There is also a possibility that a bulb is burned out or there is a short in the wiring.
did you check the fuse?
Usually a fuse. when the fuse blows the dash lights AND tail lights dont work. If your tail lights work and dash lights dont, check bulbs, if all blown at once you may have a shorting problem. If bulbs are good you may have a bad connection. Tracing wires is a big job. Get yourself a good quality test light.
Do parking and taillights work? If not check fuse--common circuit