How to turn off the Door Ajar Light on a Ford vehicle

Understanding the Door Ajar Light Problem On Ford Vehicles

If you have a door ajar light on issue on a Ford product, the problem is almost always due to dirt and crud jamming the plunger on the door latch switch. However, the problem can also be due to body control module, or a broken wire in the door hinge area.  Here’s how the system works.

How the Door ajar light on problem occurs on a Ford vehicle

The door-ajar switch is located at the bottom of the door latch.

The door latch and door ajar switch at the bottom

It’s a really stupid design because any dirt and debris that enters the latch, falls to the bottom where the plunger switch is located. The dirt jams the plunger, so it can’t pop up.

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 the ground. The BCM sees the voltage drop and turns off the door-ajar light. If 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.

But a stuck plunger switch is the most common cause

First, try lubricating the door ajar switch. Shoot a light lubricating oil like WD-40 or PB Blaster into the latch, aiming the straw down toward the plunger switch. Then 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 green/violet, white, green, or yellow. The ground wire will be black/white or black/yellow. It you see

Door ajar switch

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.

How to replace the plunger switch

• Remove the door trim panel and vapor barrier

• Using a leather gloved hand (sharp edges inside the door) twist the plunger switch to disengage it from the latch. • Remove and replace.

• Reverse the procedure to install the new switch.

©, 2017 Rick Muscoplat