If your door lock or unlocking function fails here are a few common areas to check.
- If the door locks and unlocks with the console switch but not the remote, the issue is likely a battery or contact issue from the remote. Alternately, if the remote works fine but the console buttons have issues then it is likely a switch issue on the console.
- If the console switch works in one direction and not the other it could be the copper traces located in the console switch went bad. If the console door lock does not work in either direction the problem is most likely related to your door lock power motor or somewhere in the circuit. The motor is sealed from the factory, but if you live in a wet climate or keep the truck outside there is a high probability that moisture entered and corroded the internals. I have repaired many door locks and see some very bad corrosion inside. Below is a picture of the door lock of the SSR and the location of the motor.
- Testing Motor – To test the motor, remove the door lock assembly from the door, then power the connector via the 2 pins on the motor marked number 1 in the image below. Does not matter what pins you use to power the 12vdc positive or negative, just place one lead on one and another lead on the other. If you do not hear the motor and view the lever at the bottom of the lock operate when power is applied or the motor seems weak, you most likely found the problem with the door lock. You can reverse the 12vdc wires used at the plug and test for the the opposite action, lock or unlock signal. If everything on the door lock actuator works fine, you need to test the wiring and relays that feed the door.
- Testing Lock Signal – The signal starts in the Body Control Module (BCM), then runs through some relays and then to the respective wiring for left and right doors. See the schematic here. Using a voltmeter might be unreliable due to the voltage signal. The signal used is a short burst to operate the motor, not a long term steady signal. As such, viewing the signal on a meter might be missed. Using a 12vdc circuit test light will help with visual indications of the signal. Simply attach one end of the tester to ground and the other end to the truck side of the 2 connector plug for the motor, then have someone actuate the lock switch on the console in both directions. When the console switch is pressed in one direction, it should light up the light for an instant on one of the plug pins. The same for the other pin in the plug. If you get no signals at the plug it could be a wiring issue at the door pivot area, bad relay or failed BCM.
- Replace drive motor on door latch – If you tested the door latch motor and found that it does not respond to 12 VDC you can replace just the motor. To gain access to the drive motor you will need to cut open the small back plastic case where it was sealed, this area is marked number 1 below. I normally use a dremel tool to cut the case open. Once you have it open you can most likely see all the corrosion inside the case. Simply remove the bad motor, then replace it with another item from a new assembly from EBay or a parts store. Look for a door lock actuator motor, it will look like the second image below, one part number for this is a Dorman 746-011. You will need to cut this new motor case apart as well to gain access to just the motor and use it for the replacement. When complete, replace the plastic cover and seal it where it was cut. I normally use an old soldering iron to weld the plastic case and then use some black RTV over the areas I worked to insure a good seal.
If you would rather not work on it or need a NEW driver or passenger door lock mechanism please let me know via the Contact Form link above as I have them available. They are not OEM but are excellent replacements and function 100% like the OEM.
