Dashboard lights wont come on

The first thing I would check is to see if any of the wires you changed grounded out and caused a fuse to blow. Also it is possible that when you hooked up the lights to the radio it went to the wrong wire causing the problem. Also it is possible that as you worked putting in the radio you accidentally came in contact that feeds the dash lights. So check your fuses that controls the dash lights.
If you pulled the dash panel the dimmer adjustment on the light switch may have been turned off.

you need new wiring for your radio, a new radio, new speakers, new wires going to your light and a new light. hooking up a battery wrong can destroy a car. your lucky it didn't catch fire.

Try disconnecting the negative bbattery cable for 5 minutes to reset the system control module, if that doesn't do it you will need the dealer to look at this.

You hooked one of your wires to the wire that runs the illumination lights on the factory radio. Then it blew the parking light fuse. Check the fuse and your radio connections.

You probably touched a wire wrong and blew the fuse for nighttime illumination, same fuse that lights up the dash. Also, you might've hooked up the vehicle illumination wire wrong in the back of the new radio, causing a short and the fuse blew

I had a BMW 540i 2000 and that happen to me, my advice is to get the battery out of the car and recharge it. It would be advisable to have it check for malfunctioning. If it is ok, put it back on and the car will start. If not good, put a new battery, the car will start and all the lights will work in order.

Probably you could loos your radio set up and clock set up if you took too much time in the replacement of the battery, don't worry, reset the clock and the radio stations.

Yes it is a fuse

You have wired something wrong. Find a different power wire for your radio. Best to hook a power wire into the fuse box, and have an inline fuse for you radio. And then run a ground wire to your steering column or something.
If it's not that, then you must have pulled a wire off somewhere, and now it's grounding out and blowing your fuse. Have fun. Wiring sucks!

Pull it back out, (Radio) and recheck your steps. Something is not hooked up right. When you pull it back out, See if it goes back working normal. Retrack the wires. You cut are hook up something wrong????

Start with the fuse box and a new battery if you haven't already got one installed. Does it run?