I have a 2002 ford explorer and sometimes my (new) key fob stops working and when that happens my parking lights wont shut off so I have to reprogram the car to the fob again and it fixes till it happens again. What could be causing this?

Was tested with many different fobs and same results. What I don't understand is why the parking/approach lights wont shut off? They turn on when I hit the power lock or open any door and usually go off after a few seconds when the door is closed, but for some reason they don't turn off and usually it is at the same time the fob stops working. Was thinking to replace the approach light relay but I cant find the fuse panel "The relay box is located on the rear passenger side quarter trim panel. To access this box you must remove the trim panel." Got me I looked everywhere. Also shouldn't the battery saver shut the lights off after 10 minutes? I waited longer than that but it didn't.

Well it is all fixed. The parking lights were not going off and there other issues do to the instrument cluster not working correctly (was replaced). The thing with the fob was that a car starter was added after vehicle was originally purchased by the owner at the time, so when I bought it I did not receive any fobs or whatever. So doors were set up to work with the transmitter for the starter. I went to a place that deals in starters and they sold me a new remote which has all the buttons to lock and unlock etc. So everything is working great now and I can now start my suv from my warm home hehe. The mechanics I went to were very good they they were able to find and repair many broken wires and replace the instrument cluster. They were baffled by the fob not working till they realized there was a separate antenna hanging from my rear view mirror than they told me where I needed to go to get a remote. I am very happy it all worked out.