Door Lock Actuator Hell... Need Advice Please!!

[lsfeder]

Hello Everyone,
I am at my wits end with my car. 2004 FX35 with about 70K on it. My left rear passenger door lock is acting up in a way that I dont know what could be the cause. Here is the story: In 2010 I replaced the same actuator because it would not lock/unlock as it should (normal issue). Fast forward to about a month ago, on a road trip all of a sudden the same door would not open at all. Unlocking/locking both electronically and manually had no effect. I read online that this issue has happened to other Nissan owners, and the only way to release the door is by obliterating the actuator to physically manipulate the mechanism. So I ordered a new part, and destroyed the old lock, got the door open, installed the new part. The door opened and closed perfectly fine from inside and outside, so I then proceeded to do a lock test. I shut the door, locked the car, attempted to open the door from outside with the doors locked to make sure it was locking properly. Then I unlocked all the doors, and now the stupid door is jammed shut again!! Manually manipulating the locks makes no difference. I opened all doors to see if maybe another actuator was failing, but nothing. Disconnected the car battery and manually opened the lock, still no response, the thing is jammed shut again. There must be something I am missing here, since I doubt its the actuator (its brand new!!). And I cant bring myself to now have to obliterate a brand new actuator that cost me 200 effing dollars. Has anyone seen or heard of anything like this before? What should I do? All advise is appreciated.

Thanks!

[MinisterofDOOM]

If multiple modules have failed or exibit flaky behavior, I would suspect wiring or the main control module. Since it's specific to a single door, I'd probably suspect wiring.

If you know your way around a Factory Service Manual and a multimeter, you can test voltage at the harness upon power lock actuation to see if things look right. You can get the FSM for your car here.