Interior lights not working no power to a/c no power to rear defroster trunk button not working volt meter on dash reads xxxxx

Do you know what a electrical distribution diagram is ? Free diagrams here http://www.bbbind.com/free-tsb enter vehicle info. under system click electrical distribution then under subsystem click power distribution . Click the search button then the blue link. see where their power comes from (test up stream ) fuse ,relay , ignition switch .

What body fuse ? The body functions on your vehicle are controlled by three different control module . The IPM - instrument panel integration module ,the DIM - dash integration module an the RIM - rear integration module. Having the vehicle scanned for DTC'S - diagnostic trouble code's should always be the first step in a diagnostic procedure for this type problem . Not at auto zone or advance etc.... they can not pull code's from the body computers . When you push the button for the rear defroster ,trunk release ,these are input's to one of the front modules which will send a message over the class 2 data bus to the rear module which will energize a relay to pop the trunk or turn on the rear defroster . The rear module also controls the interior light's . Your best bet , take it to a qualified repair shop.

Have you tried adjusted the dimmer switch??Some other things to check are your grounds and the charging system.The ground between the engine block and firewall/chassis is the ground for the interior & exterior lights so make sure its tight and corrosion free.
The next thing you should do is conduct a full charging system test. Here’s how to do your own.
Connect a digital volt meter to the battery terminals. A fully charged battery should read about 12.7-volts. Start the engine. The reading should jump to around 13.5 volts. Leave the engine running and turn the blower motor to HIGH. The reading should dip down and then rebound back to 13.5 or more volts. Leave the blower on and turn on the headlights. It’ll dip again and rebound. Then turn on the rear defroster grid. Next, sit and watch the meter for about 10 minutes with the engine running and all those accessories on full blast. If the voltage stays the same at 13.5 or higher, the charging system is fine. A weak alternator will start pulling the voltage down in small increments because it can’t keep up with the electrical drain.

That is normal there is a dile on the dash that controls the timer on that.

There are only 3 things to look for, 1, is there power at demister checked with a volt meter on the wire connector on the back window. 2, is the earth wire connected again with a volt meter at the back window. and lucky last,3, check the ohms on the back window

Some vehicles have a primary fuse box under the hood, these have heavy duty 20-60 amp spade fuses, usually located close to the battery, some supply sections of the interior fuse panel, if you pop one of these a lot of things will not work, hope ill fixya

Check your power feed wires that come from the battery positive cable.

More than likely it is probably a blown fuse. Locate the fuse panel, normally under the dash on the drivers side, or on the side of the dash between the door and the dash, and you can test your fuses with a test light or volt meter if you have one available. if the fuses are good both sides should show the same thing.

Jeff, If you have already checked the fuses, check the wires attached to the defroster Grid. You may be able to see them inside the rear window. Make sure they are still connected. You might also want to check in the trunk the wires may run into it, and might have peen pulled apart when you put somthing in the trunk. As a last resort take a continuity tester and check the grid itself to make sure it hasn't failed altogether. Un plug the wires b-4 you test it to avoid a false reading.

You have a wiring harness problem
Take it to the dealer directly.......