1997 corolla DX, 251K miles with power windows and door locks. No key fobs or remote door openers/starters. The doors instantly lock when you push the unlock switch on either the drivers or passengers door. When you manually raise the "lock button", the door will relock itself within minutes. When you use the key in the door and single twist to open the drivers door, it instantly relocks. When you double twist, all four doors instantly relock. Any idea of what the problem is? Possibly the power door relay? Where is it? How do I get to it to replace it? Possibly the drivers door switch due to wear? ideas?