If the door ajar light is coming on in your gauge cluster, and the warning chime is sounding when all your doors, liftgate, and glass hatch are securely shut you most likely have a sticking door ajar switch. The door ajar switches are inside the doors mounted on the latch mechanisms.
In a 2002 Ford Explorer : ( relay # 48 is the fuel pump relay ) In the Power Distribution Box ( which is " live " ) located in the engine compartment
On a 2002 Ford Explorer - ( 4 door) in the power distribution box there is : in location # 12 - a red color 50 amp maxi cartridge fuse for the starter relay and ignition relay and in location # 56 is the starter relay (also in location # 58 is the ignition relay) (Helpfull)
Hire a mechanic!
Try to replace the starter relay
On a 2002 Ford Explorer : In the Power Distribution Box ( which is " live " ) located in the engine compartment by the brake fluid reservoir ( # 48 is the fuel pump relay ) * also , mini fuse # 26 is a 15 amp fuse for the fuel pump
around $250.00 at MIDAS
"http://wiki.answers.com/Q/How_do_you_replace_the_fuel_filter_on_a_2002_Ford_Explorer"
It is found on the passenger side foot well on the outer wall.
2002 ford explorer xls 6 cylinder labor radiator cost
Replace the fuse and the relay called the CCRM (Constant Control Relay Module).
On a 2002 4 door Ford Explorer, the turn signal flasher relay is relay # 1 on the top side of the fuse panel located on the driver's side under the dash. To access the relays you must remove the fuse panel - see the dealer. On the visible side of the fuse panel in location # 5 there is a 15 amp fuse for the flasher relay (turn signals/hazard lights)
Short in the wiring, horn switch defective, or horn relay going bad.