Why won't my dash lights work?

Yes , its probably the additional wiring added with the cd player ,

A diagnostic computer wont help you with this problem , So dont waste money renting one .

have u checked the fuses ?

Did you do a visual check or test the fuses with a Multimeter ?

Reason I ask is often fuses can "Look" OK but are actually faulty , The easiest way to test them is with a Multimeter set on the Low Ohms scale or the Test Continutity scale.

May be the instrument brightness control if the fuses test OK .

But more likely something is unplugged on the rear of the Dash Panel / Dash Pod .

Has anyone done any work in and or around the dash just prior to your loss of instrument lights ?

I have checked fuses. Now someone says it may be a bulb? How can I tell?

I would suggest taking it back to the place you had the car stereo installed at. if they are reputable they should check it out for you.

I bought the car like this? IDK where it was installed. :/