My passenger door lock, I've replaced it twice in the 3 years I've owned my truck. It seizes up and refuses to budge. It was on the fritz a few weeks ago (power lock switch pressed, then it struggles to move). Today I opened it by hand, and it took my key outside my door AND my hand on the lock switch inside the truck to get is just barely into the locking position. It was so incredibly stiff. Anyone else experience this problem, or know what could be causing it? My only guess could be maybe a water leak into the door dripping onto it or something, but that's pure speculation.