the door locks are wired up with a system that is called a 5-wire reversing polarity rest at ground system. Its every bit as technical as it sounds but being lazy we shorten it to being called a 5-wire system. The advantage to it is that it uses no relays, the switches to all the work so it saves on mechanical/electrical parts but the bad part is that is a royal PIA to trouble shoot. It uses a master/slave switch system that depends on ALL of the contacts/wires being connected or else it starts to do some weird things where both switches might only unlock/lock or suddenly then are both dead. It sucks to trouble shoot because it could be a bad switch, or a bad connection between them and that leaves a lot of wire to trace to figure out where it became disconnected. If there was a spot you were kicking at one point to get it to work then start there. The lock wires are all pink with different stripe indicators on them with pink/yellow and pink/green being the lock/unlock wires but if any of those pink wires are disconnected it can cause problems. There should be a harness in there check it out to ensure all the wires are still connected and don't be afraid to give them a good pull/tug to see if the pins have slipped out of the harness and are not making contact. If you can't see anything and it still is not working try to trace that harness as far as you can to ensure that there is not a wire possibly cut by a previous alarm/keyless entry install which if you know of one should be the 2nd place to check