Diagnose and fix door ajar light on Ford
If you have a door ajar light on issue, the problem can be the door ajar switch, the body control module, or a broken wire in the door hinge area. Here’s how the system works.
Door ajar light on Ford system
The door ajar switch is located at the bottom
of the door latch. It’s a really stupid location because dirt and grease that falls into the latch can really much up the pin switch. The body control module sends power to the door ajar switch on the green/violet wire. When the door is closed and the door ajar switch is operating properly, the switch is closed and the BCM power is connected to ground. The BCM sees the voltage drop and turns off the door ajar light. If either the BCM signal or the ground wire breaks in the door hinge/jamb area (most likely place to break), the BCM won’t see the voltage drop and will turn the door ajar light on even if the door is closed.
Fix door ajar light on Ford
First, try lubricating the door ajar switch. Shoot a light lubricating oil into the latch and open and close the door several times to work the lube into the pin switch. If that doesn’t work, disconnect the electrical connector at the door latch and test for BCM power and ground.
The BCM power will be either a green/violet, white, green or yellow. The ground wire will be black/white or black/yellow. It you see
power and ground, that confirms the wiring is good and the switch is bad. To double check, jumper the BCM power and ground together. The door ajar light should turn off. If so, replace the door ajar switch.
©, 2017 Rick MuscoplatPosted on by Rick Muscoplat