Nissan Repair: 1993 Nissan Maxima Keypad Entry, nissan maxima, moon roof

Question
I really don't think I will be able to do that myself.  Where or who should I have look at the lock?  Any idea on how much it will cost?  Thank you for your help.
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-----Question-----
I just bought a 1993 Nissan Maxima. The drivers side door has a broken key lock (I can not open the door with the key). I can open the passenger side door with the key.  I can not open the truck with the key either.  I found the keypad reset code behind the glove box.  I reset the keypad and entered a new code.  Using the new code on the keypad I can open the window, truck and moon roof but not the doors.  I do hear a clicking sound around the dashboard when I am using the keypad to open the doors.  Do you have any ideas what is going on?  Thank you for your help.
-----Answer-----
Donna,

The mechanism on the inside of the drivers door is defective.  You probably have a defectivbe electric lock and it is keeping the key from turning or th edoor from unlocking when you use the pad.  I would take the door panel off and sheck out the lock mechanism when it is activated.  I met the electric lock motor is bad.

Answer
Donna,

Most wrecking yards do work as well as sell parts.  I would check the local yards for the parts and help with the install.  That is the cheap way out.  If you did this at the dealer you are looking at over $500 bucks.  Wrecking yard about $100 bucks.