I installed a pioneer head unit in my 03 civic sedan last night, and ever since my tail lights have not worked. headlights, turn signals, and brake lights are ok. Also the backlit buttons and dials are no longer lit for the a/c controls. Any suggestions?

Thanks

 

Did you use a wiring harness adapter? Or did you cut the plug and splice it, and possibly blow a fuse?
Check fuses under the dash and under the hood, check all the connectors around the area you worked near.

 

I used a wiring harness adapter. I checked both the engine compartment, and under the stearing column for a fuse labeled for the tail lights, but nothing was labeled as such

Any ideas?

 

Since you used the harness adapter, did you connect the orange wires to anything? Unless you have a dimmer feature on your A.M. deck, you shouldn't have connected them to anything. Even then, you would only connect one of them from the adapter to the A.M. deck. In fact, it's a good idea to just pull them out of the plug, or cap them off since they could ground out and cause an issue.
It does sound like you blew a fuse though, if the dash lights and tail lights are out. What about your front marker lights? I'd be willing to bet they are not working as well.
The fuse label should say something to the effect of parking lights, or p - lights. Get out your owner's manual, and see which fuse, or fuses, could be in the light circuit. Since some circuits are effected by more than one fuse, the best thing to do is use a meter to check them all.
If you take a voltmeter or multimeter, set it to test for DC voltage. With the light switch turned on, and the key in the ignition state (everything on, but not running) go through both panels testing each fuse. The fuses have tiny access points on either side of the top of the fuse, so you can probe them with the meter's leads. With the common lead of the meter touching a good ground (bare metal), go fuse by fuse with the other test lead, testing each side for the same voltage reading. If you come across one that does show voltage on one side, but not the other, you've found a blown fuse. If after replacing it with a good one, and the lights still do not work, contunue testing where you left off. Also, if you replace it, and it blows immediately, or when you replace it and turn the lights on with the switch, and you hear a pop (like a snapping sound), you have a grounded out circuit.

 

thanks ibjamn. I think that may be the issue. I appreciate all your help. you're going to save me a lot of headache and money!