Police Interceptor "Dark Car" Option

Many crown victoria police interceptors have the "dark car" option enabled. When a door is opened, the domelight will not illuminate, but the overhead interior light will operate when the headlight switch is pushed in to turn on the domelight. At first, I thought the stealthy "dark car" option was a neat feature, but it quickly became an annoyance after a couple of weeks. If you're observant, you'll notice that the car does know when the drivers door is open because the key in ignition buzzer engages when keys are in ignition and drivers door is opened, and it also enages if the headlights are left on and the drivers door is opened.

To re-enable the domelights to turn on when a door is opened, seperate the blue male and female single wire connectors on the passengers side of the car under the glove box. Then disconnect the negative terminal from the car's battery, leave it disconnected for a couple minutes, and reconnect. The "dark car" option should now be disabled.

Note: A pair of pliers may be useful to seperate the connectors, they can be very stubborn and not want to pull apart from one another easily. If you get desperate, cutting the single black wire running out of the connector will work as well. Make sure to tape up the exposed ends if you choose this route.

Also note that it if the vehicle's battery is not disconnected after the dark mode connectors are seperated, the lcm will typically exit dark mode too. But it will take countless door open/close events until the domelight mysteriously springs to life. And even this will vary depending on which software version your lighting computer runs on.

It is also possible to refresh the lcm's keep alive memory by pulling fuses instead of disconnecting the battery, but the power distribution systems varies in crown vics depending on model year and the lcm is also fed off of a couple different circuits. So you'd have to pull more than one fuse, and which fuses to pull would also vary. Hence, the suggestion to disconnect the vehicles battery which effectively removes all the fuses in one quick step.

This article is only relevant to 1995 and later crown victoria police interceptors, the connector in question is not present on earlier vehicles. 1994 and prior crown vics use a conventional parallel/series wiring setup for domelight illumination. 1995 and later ones use a lighting control module and the domelights can be disabled by grounding one of the LCM pins when it is not desirable for the courtesy lights to illuminate when a door is opened.

Note: Instead of conventional pin switches on the door jamb, 1995 and later crown vics use a door ajar switch located inside the door on top of the latch mechanism. Is not uncommon for these switches to fail and short to ground, so domelight illuminates constantly and will not shut off. Also, some police departments cut the wire running to the drivers door ajar switch since this disables the key in ignition buzzer and parking light reminder buzzer. See the door latch article for further details on this topic.

A few crown vic owners have asked how to retrofit the dark car option onto their civilian models. Below are a few solutions:

Remove all the bulbs from the courtesy light sockets
Cut the courtesy light output wire at the back of the LCM
Cut the door ajar wire inputs at the back of the LCM. This will also disable the key in ignition and headlight warning buzzers.
Add the dark car pin to civilian LCM connector and ground the wire. Note that to toggle between dark mode and normal lighting mode, one would have to disconnect the vehicle's battery or momentarily remove the fuses that power the LCM's keepalive memory.