Try chamging the bulb, and if that doesnt solve your problem, check all the wiring.
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.
you have a blown fuse, look in your owners manual and it will show you the fuses location.
turn the knob on the left side of the steering wheel on the dash. It will brighten the dash, and radio lights by turning it to the right and it will dim the lights by turning it to the left.
it could be that your brake light switch under your dash that sits right on top of your brake pedal has gone out
most likely a blown fuse, replace, if it blows again you have a short, if you have a trailer connection look there first
bulbs blown on high side or wiring shorted
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.
brake lights dont work
depending on the vehicle, most have a circuit board where the rear lights go in then on to the rear light covers.these tend to go out with time. you should pull the plug and test the wires to see if they have fire. if they dont then it will be the brake light switch located on the brake pedal under the dash. if it does have fire then it is the circuit boards.
brake lights dont work start here check break light fuse check bulbs in tail lights check stop light switch on brake pedal under dash if problem still exists there is a break or short somewhere in the wiring
it is possible that u may have used a wire that is also used in the same circuit as the dash lights which would cause a parrellel path for the current and therefore might not be neccesarily supplying enough current to the dash lights was the stereo put in by a proffesional
change the brake lights check the fuse check the brake light swtch