2003-2005 Crown Victoria and Grand Marquis Headlights dropping out while driving

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TechSmart Lighting Control Module  (LCM)

The LCM is Fords answer to problems with electronic interference and excessive heat with thermoelectric devices used previously.
The LCM is a microprocessor based module that controls several exterior lighting systems.
System include headlamps with auto-lamps (if equipped), turn-signals/hazards, corning lamps, parking lamps and battery saver.

Most common problem with the Lighting control module is that the headlights stop working for short periods of time while driving. Due to the relay in the control module over-heating. Ford recommends only using headlight bulbs that meet there specifications, as this may cause or contribute to this condition.

Ford headlamp bulb specifications – Bulb part # 9007
-low beam light should be rated at 4.30 amps @ 55 watts,
-high beam should be rated at 5.08 amps @ 65 watts.

Before replacing the LCM, make sure all fuses and relays for the exterior lights are good. Refer to you owners manual for fuse/relay locations.
Where is the LCM located? The Lighting Control Module (LCM) would be located, behind center lower of dashboard.

2003-2004 Ford Crown Victoria, 2003-2004 Mercury Grand Marquis part # S41006

2005 Ford Crown Victoria, 2005 Mercury Grand Marquis part # S41007




ASE Certified Technician

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3 Responses

  1. Brian, thank you for your continued support of TechSmart. We’d like to talk to you about working with us on future products. We couldn’t find an email for you but please contact us at TechSmart@smpcorp.com. Thanks again.

  2. JimBo says:

    Open this unit and on the top circuit board you will see 4 black relays. NEC EQ1-11111S. Mouser.com has them for about $5.00 each. I replaced a relay that had dark stains around it four years ago. Mouser shows this part as being discontinued. For the difference in price for replacing the whole unit you can buy all the tools you need to do this and still save $200.00!

  3. steve says:

    Dorman is now making a repair module , that is much cheaper than the Ford replacement part

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