Lights are stuck ON - Even with new LCM

115

Asked by Jul 13, 2015 at 03:11 PM about the 2003 Mercury Grand Marquis LSE

Question type: Maintenance & Repair

My automatic headlights are stuck on, regardless of the position of the headlight switch,
as long as the key is on.  (They go off when the key is off.)  I've replaced the LCM, and
the turn signal/wiper switch is new.  Should I replace the dash switch?  Where is the light
sensor?  With the red anti-theft light on top of the dash?  Will it need to be replaced, too?  
It's not a big deal, but it's kind of irritating.

5 Answers

54,535

Where did you get the LCM? If it is an after market unit such as Dorman that maybe the problem. The LCM units in these cars have extended warranty from Ford and your's will still be under warranty if the LCM is the problem. The Dorman units are pretty much junk and have been known to cause problems.

115

It's rebuilt; it's the second one. I replaced it as soon as I noticed the lights were stuck. I haven't pushed trying to get a new one from Ford since I replaced the first one years ago.

54,535

They are still under warranty. Something like 250,000 miles and 15 years.

115

263K+ here... I'm getting my money's worth out of this car!

54,535

LOL, You may be able to remove the LCM and resolder the bad solder joints (talking about an LCM that is the same as the original not an aftermarket unit). That is usually what happens to them. Google LCM repair.

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