Why Do Car Interior Lights Not Turn On When the Door Is Open?

Why Do Car Interior Lights Not Turn On When the Door Is Open?

So your car’s interior lights do not turn on automatically when the door is open? What could be the reason?

Interior Lights is a broad term encompassing a variety of lights inside a car like the dome light that’s usually located overhead and illuminates the car interiors when switched on, dashboard lights, map lights, stepwell lights, etc.

There are several reasons why interior lights stop working and do not turn on automatically when the door is open, like an incorrectly set dimmer switch, dimmer position, a short circuit, a blown fuse, burned-out bulbs, or bad door switches. Let’s shed some more light on these causes and see how you can fix them.

1. Dimmer Switch

If the dimmer switch has been turned off manually or messed with otherwise, it will stay in the off-state and fail to override the automatic turn-on signal when the car door’s open. Check the position of the dimmer switch and make sure it’s set in the correct order. Some car dome lights have multiple switches. If that’s the case with your car, ensure all the switches are left in the proper state not to override the automatic turn-on signal.

If the switches aren’t the problem, you’ll have to look for shorted wires in the switch circuits.

2. Short Circuit

Look for burnt wires in the underlying circuits that connect these lights to their power sources. If one or more of the wires are burnt, you’ll need to replace them asap.

3. Blown Fuse

The surest way to know if you’re dealing with a blown fuse is to check whether all the interior lights have stopped working at the same time, even as other electronics like the speakers or radio are working fine. If so, it means that the problem is in the main fuse box that powers all the lights.

Depending on the brand of the car, fuse boxes can be located anywhere, like in the engine compartment or around the glovebox. Locate your fuse box with the help of your car manual if you want to solve this problem.

Usually, there are no visual indicators that a fuse box is not working as intended,  which is why you can’t judge whether a fuse box is working fine or not based on how it looks. Once you’ve located the fuse box, or boxes depending on your car’s make, use a multimeter or a test light to check whether the fuse box has faulty circuits. If there are breaks in the circuits, you’ll need to replace the defective wiring to fix the issue.

4. Burned-Out Bulbs

If the bulb of the interior light is blown out, it will not turn on. This is the most straightforward issue to identify as well as fix. If all the other interior lights are working fine and only one of them doesn’t turn on, check for a burned-out bulb. Simply replace the bulb to resolve the issue.

5. Door Jamb Switches

Door jamb switches are located in the door jambs of most cars and are programmed to turn on when the door is opened. If there’s no fault with the bulbs, switches, wires, and fuse box, you might want to check whether the fault lies with the switches in the doors.

You’ll need a flat blade screwdriver to uncover these switches, which are usually covered with rubber boots. Once you’ve managed to locate them, use a multimeter to check whether the switches are working as intended. If not, you’ll have to replace the wiring or the switch entirely.

If none of the above tests yield positive results, you could be dealing with advanced stuff like a faulty interior lights module that’s too complicated for non-professionals to troubleshoot. Consult a mechanic or visit a service center to resolve this issue.

Car interior lights’ problems are usually easy to locate and fix without professional help. Just keep the car manual, a multimeter, a test bulb, and your trusted toolbox handy to get to the bottom of the problem and fix it.