Interior door lock

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by BajaMark, Oct 16, 2012.

  1. BajaMark

    BajaMark New Member

    My interior door lock has stopped working 99 Chevy Silverado. It unlocks manually using the key in the outside door lock, but does not work with either driver or passenger interior unlock/lock button. Both buttons operate the passenger lock just fine. When pressing the lock button the lock will move slightly as if it wants to close, but when pressing the unlock button lock is completely unresponsive. Any advice what to replace or check please advise

    Also just to throw it in my headlights are alwAys on, which makes me think my auto dash sensor has gone bad, anything else I should check? Thanks for the replies
  2. RayVoy

    RayVoy Active Member

    You could have a failed light sensor, what is the condition of the dash lights? For example, in the daylight, the radio display should be a lot brighter than at night.

    I don't have a wiring diagram for your truck. If the dash lights appear to be operating as they should, you probably have a stuck headlight relay. Check the fuse panel to find it.

    While in the fuse panel(s), look for a driver's door fuse. If the lock tries to lock, then your fuse is probably ok, but check 'em anyway. If the fuses are good, there may be some rust in the lock mech preventing it from working. When you turn it with the key, does it turn easy, or somewhat hard to turn?
  3. Pikey

    Pikey Moderator Staff Member

    The door lock issue could be a failing door lock actuator. My 02 did the same thing, I replaced the actuator and it worked fine. I would pull the door panel off and look around in there. There could be a rust issue like [MENTION=54249]RayVoy[/MENTION] stated. After you get the panel off, reconnect the switch and try locking/unlocking. See if the actuator is moving or if it is frozen in place. They are around $37 at autozone if you have the anti-theft system, if no ant-theft they are $70.
  4. BajaMark

    BajaMark New Member

    Thank you all for the replies. I will check the brightness of the interior lights during the day tomorrow, however to my knowledge I people they are normal.

    I will pull the door panel off this weekend and check those areas. The door works smoothly with the key. However when I throw it into park and it tries to unlock, sometimes I have to relock it then unlock it manually, because it is stuck in the middle. I will advise if I fix it or become stumped, thank you again.
  5. j cat

    j cat Active Member

    the head lights coming on when its bright outside is the light sensor as many have had this occur. on my vehicle over the years this sensor makes the headlights come on much sooner than when new as the daylight fades.
  6. BajaMark

    BajaMark New Member

    Okay got the door panel off today and in still stumped. The lock is a little tougher to move than the passenger side, but still pretty easy. I sprayed everything down with wd40 and greased up the areas of contact. For the relays, I removed one and the passenger side worked just fine. Then I removed the other one, and nothing worked. I switched them and passenger side went back to working again. Could the relay still operate the passenger side if it was dead for the driver side? Or could this be a problem in the mechanism inside the door? Also, there is a loud clicking sound coming from the relays.

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