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Ford Crown Victoria/Mercury Grand Marquis Electrical/Lighting

124

Comments

  • sparky5870sparky5870 Member Posts: 2
    i'm looking for a junction in the wiring harness because i can't reach the individual door button switches in the door frames? only cause for all of the interior lites to remain on would be if the headlight switch is turned to the right. any other suggestions?
  • swrbooswrboo Member Posts: 3
    My mercury just started developing electrical problems today. I first noticed that the clock went out as well as the cig lighter and power point. I went out tonight after dark and realized too I have no dome light, head lights or parking lights. the turn signals and radio and everything else works ok. The only thing I have not checked yet is the wipers. I checked all the fuses in the cabin and they all check out ok. Any suggestions? I don't have much money but if someone can offer advice on where to look for the prob i will try to dig into it myself and see if i can fix it relatively cheap rather then pay a Ford dealer. Please help. I need my car to get to work and its is dark when i get off work, so i need working headlights
  • euphoniumeuphonium Member Posts: 3,425
    On the driver's side of the engine bay there is a Black box containing a set of circuit breakers. Check it out according to your Owners Manual.

    Try to reset the on board computer by disconnecting the Negative battery cable for a few minutes and then reconnecting it.

    If you're good at removing the cable, remove both cablrs and clean the terminals with a post cleaner & use the wire brush end to clean out the center of the cables.

    Corrosian diminishes energy to the accessories.
  • brookfieldrichbrookfieldrich Member Posts: 5
    My auto headlights on my 2003 Merc Grand Marquis do not work consistently. They turn on intermittently and rarely when I need them at night. If I run the emergency flashers while driving at least 2 minutes they sometimes come on. Also, if I use the security keypad on my door to unlock the car they sometimes come on. I have been driving while holding the "flash to pass" control and will get a high beam that works for now. If I push the high beam control forward toward hood nothing happens. I'm out of work and am looking for some "do it yourself" suggestions. I'm not afraid to do the work but do not know my way around this car.
    Thanks
  • brookfieldrichbrookfieldrich Member Posts: 5
    Thanks njadams. I will give them a try and post back when I run through the process.
  • jim416jim416 Member Posts: 1
    I have a 98 crown vic that the headlights quit working. the flash to pass will turn on the headlights when held but not the switch. I have tried a different lcm from two different lcms from unwrecked cars from junk yard. still no luck. when i turn the light switch to parking lights I hear the relay click and the parking lights come on. when i turn the switch to lights I hear the relay click but no headlights. since the car was new i have run it with the photo sensor covered with electrical tape to make it think it was dark so the lights would be on all of the time. i don,t know if there is another relay that may be having a problem. any ideas ?
  • andy136andy136 Member Posts: 2
    My 2003 Grand Marq. mercury has been diagnoised as having a malfunctioning "lighting control module". I paid a mercury dealer $91.50 for this info. The same dealer wants $608.50 more to repair the problem. I need to know if this total of $700.00 is a reasonable price for this and,if not, what would be a reasonable charge. My lights turn off unexpectedly but shortly come back on. I am an older guy (WW II veteran) and on a limited income. Any helpful info would be greatly appreciated.
  • euphoniumeuphonium Member Posts: 3,425
    Until the two fuse locations are checked out by an independent auto electrical tech I would hesitate on buying a new module. I believe there is a Black circuit breaker box under the hood. Hopefully, that is your source of the lights going out as that breaker opens and closes from time to time. The other fuse location, under the dash, contains fuses of different colors and when when of them blows - that's it until it is replaced. Since your lights come on later, I would inspect the breakers in the Black box under the hood.
  • gates229gates229 Member Posts: 1
    My mercury grand marquis wipers do not work. I replaced the wiper switch because a mechanic told me they go bad a lot and they still do not work. Does anyone have a idea of what it could be?
  • andy136andy136 Member Posts: 2
  • dunncustomzdunncustomz Member Posts: 1
    1999 merc grand marquie (pos) replaced the LCM , door striker switch,re adjusted door strikers and cleaned contacts in the LCM and the stricker switch. and the damn courtesy light still comes on random leaving the car dead every morning!!!! any insight to this problem would be greatful.
    oh ya did i mention thats about a thosand dollars in parts so far chasing a bug that will not squash
  • itisalljunkitisalljunk Member Posts: 1
    I would bet it's your driver's door, exterior touch button, key pad(that is if you have one). Pull the interior door panel off and unplug the key pad. They get corroded in there and cause just what you are experiencing. Unplugging it should end your problems with no ill effects. You could replace the key pad if you actually use it.
  • euphoniumeuphonium Member Posts: 3,425
    I don't know how this works, but sometimes disconnecting the battery for a couple of hours enables the "gitzensnorkle" to reset itself. Might be worth a try before removing the door panel.
  • raszmanraszman Member Posts: 4
    My '01 Grand Marquis just developed an unusual electrical problem. It started during a mountain trip. The first problem was the ABS and Trac Ctl indicators on the dash came on. Then a very unusual problem appeared - the high beam indicator illuminated and both turn signal indicators came on, but dim. The headlights and front running lights don't come on(relays clicks) The tail lights and brake lights work(allowed me to get home...) The turn signals work sometimes - blink very fast. On the highway, the turn signal and high beam indicators go out around 50mph - the A/C compressor will work when they go out. Windshield wipers work, washer doesn't. No engine codes(nor check engine light). Assume some ground issue or some control module failed?
  • raszmanraszman Member Posts: 4
    Found the electrical problem... right front fender was replaced a couple of months ago during paint job and they failed to tighten a ground wire that attaches to the fender inside......ABS light remains on - next on the list to troubleshoot!
  • speaquespeaque Member Posts: 1
    I'm having the same problem with the same year Grand Marquis. How did you resolve it? Thanks.
  • brookfieldrichbrookfieldrich Member Posts: 5
    My mechanic replaced a "multi-function" switch located underneath the steering column and that worked for me. Cost me $200 for parts and labor.
  • raszmanraszman Member Posts: 4
    I was "fortunate" that I found the body shop's failure to tighten the ground wire prior to replacing parts. The ABS indicator appears to be a separate coincidental issue. I'll clean off the sensors as others in this forum have recommended and if that fails I will have the ABS codes read I guess.
  • yooper88yooper88 Member Posts: 2
  • yooper88yooper88 Member Posts: 2
    I have a 2000 Mercury Grand Marquis. The ignition buzzer, turn signals, parking lights, headlights, dome light and hazards are not working. The brake lights do work. I checked the fuse panel info and could not find any relay or fuse that links all these indications together. Did check every fuse and did not find any bad. I don't have any schematics to see what all these have in common. Thinking possibly a bad wiring harness connector, maybe on steering column, ignition switch or battery (original). Anyone seen this problem before?
  • videoparadisevideoparadise Member Posts: 4
    i have a 2003 grand marquis. went to get an emissions sticker and the guy couldnt get a reading from the computer. told me there was no power going to the computer plug. checked all my fuses and cant find any fuses blown. manual doesnt tell you which fuse powers the data link or obd so i checked them all. not sure if a relay powers it. anyone have any ideas what to check? i have 60 days to correct this before my sticker is bad. Thanks in advance, john
  • videoparadisevideoparadise Member Posts: 4
    im sure you got it fixed by now but if you ever hear of anyone else having this problem, tell them to go to ebay. i bought a LCM (lighting control module) for $150. on ebay. it has a lifetime warrenty. very easy to install to the right of the steering colum under the dash. returned old LCM in a self addressed envelope that came with the new LCM. within days he credited me $50. so i only paid $100. all is good!
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Well before we panic here, it might be a good idea, just as a double-check, to try another scanner, say from Autozone or O'Reilly (where they usually do it for free).

    There are tests, called "Pinpoint Tests" to determine if you have some damage in the harnesses related to the PCM or the Datalink connector, or some other component failure, but you'll have to go to a repair shop that knows what they are doing. You could have a short or bad ground in some harness, yes.

    But first see if some other scanner can read.
  • videoparadisevideoparadise Member Posts: 4
    thanks for your reply. i did go to autozone, they plugged in their handheld computer and it also had no reading at all. the gentleman there said the same thing, without power to that connector he cant get a reading.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I searched to see if the data link was fused but couldn't find anything. ON some cars it is fused. Have you disconnected your battery in the last couple hundred miles?
  • videoparadisevideoparadise Member Posts: 4
    havnt disconnected the battery for a long time. ive searched my manual and cant find any fuse or relay labled as the computer fuse or relay. any idea how to figure out which one powers it? or maybe it doesnt have a fuse for it? nobody seems to know anything about this problem. no ones ever heard of this before.......just my luck.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Well yeah the problem does come up but often, say on most GM cars, there's a fuse that controls it. If there isn't, then someone has to test the various pins in the connector link and figure out why there's no power to the data link. These systems are not as standardized as one might think. I have heard that on some cars when certain components fail they will also knock out the data link, but again, I can't find anything specific to your make and model.
  • suavemikesuavemike Member Posts: 1
    Did you figure out what the issue was? I am having the exact same problem. A dime fell into my 12v cig lighter and shorted it out. I replaced the fuse to the cig lighter but now my dome lights, headlights, and clock don't work. Turn signals and radio and everything else work fine. Just the same as your vehicle. So I'm guessing what ever it is that shorted out is the same on both our vehicles. Any info would be greatly appreciated!!!
  • fordgirl4fordgirl4 Member Posts: 3
    I spent around a grand and still had the same problem. I ended up just taking the bulb out of the dome lignts, ant turning the light switch to off. I still have a dome light if I turn the switch on, so I have not had to worry about the dome light and lights coming on during the night and running my battery down. I realize this is not a fix, however it was cheap and it works!
  • euphoniumeuphonium Member Posts: 3,425
    "I ended up just taking the bulb out of the dome lignts, ant turning the light switch to off. I still have a dome light if I turn the switch on"

    If the bulb is out of the dome, how do you get a light from just turning the switch on??? ;)
  • swrbooswrboo Member Posts: 3
    Ok, I am still having electrical problems but I have narrowed it down to what I see might be the culprit. I keep blowing the big 40 amp fuse under the engine compartment that controls the headlights, parking lights, dome light, clock, and cigarette lighter and power point. BUT, I also have noticed that it seems to only blow when I leave my GPS plugged in. After a few days I can tell its getting ready to blow because the power light on the GPS goes out first. I have replaced the cord for the GPS and have plugged it into the power point rather than the cigarette lighter but still the same problem. I am thinking I have a short in the cigarette lighter somewhere. But does a short there affect the power point too? And if this is the case, where do I start to look for it? It doesn't blow the fuse in the car, just the one under the hood.
  • mrsrichmondmrsrichmond Member Posts: 1
    I had the same exact problem and i can assure u that it the head light control module(lcm) the part cost 511 new but i got a used one for 50 dollars!!!! I drove my car almost two years before i fixed it, i just drove holding the bright lights which worked just fine until i fixed the problem.
  • beach_bobbeach_bob Member Posts: 1
    I found the problem to be a defective relay within the lighting control module. My dealer will replace the module for about $900.00, first diagnostic, then program the module and install it. The part can be obtained from Mouser Electronics online for under $6.00. If you can solder it is a simple task, just locate the module which is found mounted under the lower dashboard to the passenger side of the steering column. Three plugs must be removed after you slide it out of the mounting tray. Open it up and you find four identical relays. The headlight relay is on the side opposite the long heat sink and nearest the vehicle connectors. OEM p/n NEC EQ1-11111S. There is another post here with great photos which guided me. Look for discoloration on the PC board from the heat generated by the arcing contacts.
    Good luck.
  • jvpeachjvpeach Member Posts: 2
    I have an '03 Crown Victoria and the power door locks button quit working last night along with the dome light, clock, & overhead display. The radio works but the buttons do night light up for it and the temp control buttons do not light up either nor do the ac, defrost, etc. selection buttons which means no heat or ac right now (or defrost). This is the second time this has happened. First time mechanic had it 5 days and couldn't figure it out (checked all fuses and they appeared ok). A random guy from church looked at it next and got all working other than overhead display but didn't tell me what he did. Cigerette lighter works still but even the lights on the visors are out. UGH! Any help is greatly appreciated!
  • tstacks1tstacks1 Member Posts: 1
    I cant find the other post you mentioned that has the great pictures and I was hoping you could tell me what number post to look at I am trying to fix this same problem on my dads car and would really like to see the pics before I begin. thanks in advance for any help you might provide.
  • djmrkb89djmrkb89 Member Posts: 1
    I HAVE A '00 VIC P71 & HAVE TO UNHOOK BATTERY AT NIGHT OR POSSIBLE NO START IN THE MORNING. BATTERY & ALT. TESTED GOOD IN & OUT OF CAR. FUSES GOOD. HAS ROUGH IDLE IN THE MORNING TILL WARM. SCANNED & GOT NO DATA LINK MESSAGE. ALL LIGHTS WORK BUT THE RED ONES ON THE DOORS & DASH LGHTS ARE DIM. COULD THE COMPUTER UNDER THE DASH BE THE PROB OR WHAT??
  • orientalg2003orientalg2003 Member Posts: 1
    Found the Light control module right behind passenger glove compartment. How do I remove???
  • happynow2happynow2 Member Posts: 1
    I want to thank beachbob remarks. He explained rather than pay $511 for a LCM light control module quoted from my dealer 12/15/11. Replace the relay. He was correct you will have to know someone who can unsolder the old relay and replace with new relay. The relay on my 2004 grand marquis is back ordered from -Mouser in mansfield,tx. part # 551-EQI-11111S. I found a comparable one from Well Gain electronics on the internet. The part # MR301-12HSL . The relay was under $10 plus shipping all said and done for under $20. beachbob is correct. The LCM is to the right of the steering column with 3 harness jacks. The size is about 4"wide x 7"long. After you take off 2 different under dash covers it is mounted flat on a slidemount clip to a metal housing. It's fairly easy to remove. To dismount out of open metal housing I pushed the LCM box upwards till removed from metal housing. Once you have the LCM removed you will need a star screwdriver for 2 screws and also pressing inward on the side tabs. As beachbob mentioned
    you will see yellowish/brown discoloration around the relay indicating which relay is the one to replace. I want to say thank you to beachbob for being a stand up guy in helping others in need. I didn't have the $511 for the LCM nor money to "code" the new LCM nor probaly $2oo more for the mechanic all in all arounr $800-900 dollars. I also want to thank Edmunds for a forum like this one.
  • Kirstie_HKirstie_H Administrator Posts: 11,148
    Glad you were able to solve your problem much more cheaply than anticipated!

    And we also thank beach_bob for sharing his solution. You never know what solutions might turn out to be a life (and wallet) saver for other owners.

    MODERATOR /ADMINISTRATOR
    Need help navigating? kirstie_h@edmunds.com - or send a private message by clicking on my name.
    Share your vehicle reviews

  • jigg011jigg011 Member Posts: 1
    I have 2004 Grand Marquis! As I was putting in my remote start I ended up touch the main 12v wire(green) to the metal under the dash; ground it out. I need help founded the fuse? Also, I have a number of fuses in my control panel under the dash that is not getting power. I checked and replaced fuses but still no power!

    What should I try next?
  • ct45ct45 Member Posts: 3
    I have not been able to find the pictures on the LCM repair either.

    Are they still available?
  • daveytunesdaveytunes Member Posts: 1
    Many Thanx to Everyone That offered this Info about the relays. I just repaired the LCM on My Wife's 2005 Gran Marquis with about 70,000 miles on it. It has the adjustable gas pedal and had to be unplugged before it would come out around the gas pedal motor. The soldering was fairly easy, The hardest part for Me was unplugging that single connector on top. after I figured out how to get it off the rest was a piece of cake! The Dealers DID NOT get My $$$. ;)
  • wally21wally21 Member Posts: 1
    Did you try taking off your driver door panel and disconnecting the keyless entry touchpad? The buttons corrode and cause the domelight to come on whenever.
  • downtowntaxidowntowntaxi Member Posts: 2
    edited February 2012
    .I have a 2004 crown victoria p71. out of no were my head lights turn signals interior lights dash rear defrost wiper motor and horn stoped working. ran scaner got dtc codes b1352 and b2498. check them out to be fine. giving head light switch clean power from an outside power sorce head lisght and parking lights light up but no turn signal. could go into further deatail but seeing if anyone has had a simular problems with there car. any help would be greatly apreciated.
  • railroadfrailroadf Member Posts: 2
    I am in the process of removing the LCM from an 05 Crown Vic.
    I have the box hanging down but am having trouble getting the largest of the 3 harness connectors removed. Any suggestions? Also, when I disconnected the first two harnesses, the lights came on and would not turn off until I replaced the harnesses.
  • railroadfrailroadf Member Posts: 2
    Thanks to you and beachbob. I have the box hanging down but am having difficulty getting the largest of the 3 harness connectors out. Any suggestions? Also, is the part number on the relay?
  • jvpeachjvpeach Member Posts: 2
    Does the Lighting Control Module (LCM) effect the a/c fan operation and/or is it tied to the same relay as the LCM? I have an '03 Crown Victoria and the the dome light, vanity mirror lights & overhead display don't work. The radio works but the buttons do night light up for it and the temp control buttons do not light up either nor do the ac, defrost, etc. selection buttons which means no heat or ac right now (or defrost). This is the second time this has happened. First time mechanic had it 5 days and couldn't figure it out (checked all fuses and they appeared ok). A random guy from church looked at it next and got all working other than overhead display but didn't tell me what he did. Cigerette lighter works. UGH! Any help is greatly appreciated!
  • ecoautomotiveecoautomotive Member Posts: 1
    i have a 95 grand marquis gs i found a problem on lcm i bougth another one with same part number f5ab-13c788-ae and i cant make my head ligths to turn on or interior .do i have to reset something to make the car read the lcm that im replacing? please if u had this problem before help me get this fix . :sick:
  • bigrich52bigrich52 Member Posts: 3
    07 Grand Marquis
    Door locks, rear defogger, interior light and alarm work intermittently. Checked wiring in all 4 doors nothing appears to be broken. No response when jiggled. When it rains all system work.. almost like a short of some kind but unable to locate it. I have played with the actual locking mechanism by locking and unlocking to simulate door opening / closures i did get everything working for a short time.. might have been a fluke. Can it be a computer module that works intermittent? If so what is the name of this module that controls before mentioned. Is there a home test that can be performed to single out the problem..? :confuse:
  • bigrich52bigrich52 Member Posts: 3
    I just did a manual reset to my car that i believe also pertains to your yr as well.. Disconnect neg from battery. Then take the black negative cable and touch your positive side this will not short the car but it will clear the memory.. Hope this helps
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