My 1993 Mazda 626 has an after market keyless entry. A month ago the drivers side door lock started gone wild. The lock actuator, when unlocked, bounced up and down rapidly and made a loud buzz noise before stopping at the unlock position. I went to a car repair shop enquiring the repair cost. They wanted $300 for the part and labour. I had no idea about how hard to replace the lock actuator but I felt that they want too much. The lock was still functioning so I decided not to get it fix by the repair shop. I started to do an internet research hopefully finding some resources for DIY. Having some ideas about how keyless entry work, I decided to do it myself.
Lacking the service manual, the challenge is to remove the inner door panel; I search the internet but I can’t find any web page/blog that discuss the door lock for Mazda 626. The closest thing I found was that for Mazda Maita MX-5. It said there are 4 screws which hold the door panel, and that the screws are hidden around the panel. I though that designs from the same manufacturer may follow the same line of though.
In the mean time, the lock was getting worse. Finally it failed to work at all, only making the terrible buzz noise. I spent two hours of try and error and managed to remove the inner door panel and got access to the actuator. Here is the how-to.
1. Locate the screws and remove them. The screw locations are shown below.
2. There are another 3 plastic pop rivets that hold the inner door panel. Grasp the bottom of the panel and yank it toward you to pop out the plastic rivets.
3. Then lift the panel up to release the hooks at the top of the door, and it should come right off.
4. Unplug the connectors for the speaker, the power window and the power lock.
5. After removing the inner door panel, you will see the plastic vapor barrier that covers the entire door area.
6. Peel it partially off to expose the cavity that you need to get access to the actuator.
7. Locate the actuator and remove it. It is secured by 2 screws only. Cut the wires of the actuator and taped the wire ends to prevent any short circuit.
8. Shop for a compatible actuator. It must be similar size in order to mount it at the same spot. Luckily I found one from Allelectronics.com. The spacing of the mounting hole is the same as the existing one, probably they are standard.
9. Install the new actuator and hook it up. Once you’re satisfied it works, replace the vapor barrier and reinforce it with duct tape, re-install the inner door panel and put everything back the way you found it.