2003 Aviator Rear flip down dvd Doesn't power on

You can't buy parts so the effort is a waste of time, pull the unit and have it repaired by a local authorized Ford audio shop or use one of the many online repair sites. Cost around $200

Does the window regulator motor make a sound when you press the switch for window to go up or down ?

If you hear motor running, it would be the window regulator that is bad.

If there is no noise, you would have to check for power at the switch, if you have power here, then check power at the other end of harness, where it attaches to the regulator motor. If you have power at this end, you may have a bad motor.

Do you have the rear window function locked out at the drivers switch? check it.

po420 is catalyst system efficiency below threshold. meaning is--- could be down stream 02 sensors or a bad convertor. try buy replacing down stream sensors, hopefully this may help. ( down stream 02 sensors are between convertor and tailpipe). have a good day !!

Check for a vacuum hose leak, you know for sure you do if you hear a high-pitched squeal in the engine compartment. There are vacuum lines near the rear of the engine near the firewall. Check them for holes that may have opened up from dry rotting tubes.

Tire pressure ?

here's mountaineer, it should be similar

SECTION 417-01: Exterior Lighting 2002 Explorer/Mountaineer Workshop Manual
REMOVAL AND INSTALLATION Rear Lamp Assembly —Mountaineer Removal and Installation

1. Raise the liftgate and remove the rear lamp assembly screws.

1. Remove the rear lamp assembly.
   • Disconnect the electrical connectors.

1. To install, reverse the removal procedure.
   • If necessary, install new tail lamp bulbs.

the rear seat dosent flip down in this model just the small opening behind the arm rest opens . to allow you to ccarry snow skis and such.

U must crawl under the front bumper, the lights come out from the rear.

I had a resent exp with this noise coming from my rear right... after 5 trips to Sears.... It is the parking brake shoe slaping around... ahave that wheel removed and the brake and the rotor... and behold the broken parking brake shoe will most likley fall out once the above is taken apart......