Well, actually, it's any car built on this frame, like Crown Vics, etc.
Repairing some Grand Marquis's and Crown Victorias
I owned a Grand Marquis for about 20 years. There are a couple of things I found out in that time that require some maintenance, but not the kind that should requireyou to send it off, and it could cost up to $300.
The first thing I'll talk about is the lighting control module.
The Ford Lighting Control Module (LCM), often found in Panther platform vehicles (Crown Vic, Town Car) under the driver-side dashboard, manages exterior/interior lighting and commonly fails due to worn-out internal relays, resulting inheadlight failure.
Symptoms include intermittent or non-functional headlights, high beams, and turn signals. Repairs can be made by replacing the internal relays or by using a bypass kit, which is often more reliable than sourcing a used unit. Common Affected Vehicles: Ford Crown Victoria, Lincoln Town Car, Mercury Marauder (Panther Platform). Also used on modern Ford models, such as the F-150 (2021-2023) and Escape (2017-2019).
Symptoms: Headlights (low/high beam) not working, intermittent function, or staying on when the car is off.
Location: Under the driver's side dash, between the steering column and the climate controls.
Repair Solution: Replacing the module's internal relays is a common fix, as is installing a bypass kit.
Diagnosis: Use a multimeter to check for voltage output to the lights. Recent Recalls/Issues
Some newer models (2025 Lincoln Nautilus, Mustang Mach-E) have had issues with LED driver modules, resulting in total loss of headlights.
In older models, failures aregenerally due to age-related wear on the relays.
For these issues, I can repair your module for less than about $125
Remove the old relays, solder in the new ones, and you're off.
The second thing is the AC/ Heater Control
After about 2 years of putting up with it, I finally decided to try to figure out what was wrong with my air conditioning inmy 2003 Mercury Grand Marquis. All it would do (Heat or Air) was blow through the defroster.
It had heat through the defroster.
It had AC through the defroster.
It was an equal opportunity piss-off. Wouldn't work well in summer or winter.
We live in Georgia, so both times of the year are bothersome, not too extreme in the Spring or Fall, and we can put up with it in the winter, because it doesn't get too cold. In the summer, though, it's a different story. 90-100 degrees outside, and the pathetic AC blowing through the vents was, well, pretty much worthless.
You got better cooling with the windows down.
Took it to the dealer. What a joke. "Well, buddy, your EATC (Electronic Air Temperature Controller) is probably out, or you need a new vacuum line." $100 to diagnose it (that's a hundred bucks to see if a vacuum line is holding vacuum), which is a ridiculous price. "The part is around $600 new, or you can get one on eBay for $200, costs about $100 to put it in." He said this with a serious face, without cracking a smile, coughing, or looking away, like most con men do.
I said "HAH". Cya. Bye. I'll put up with it for $600-800 dollars to fix it—no friggin way.
Then my good friend Google and I looked upon the internets for salvation, and behold, a wise man told me, "Follow these directionsand get the parts from McMaster-Carr (dot com) and do it yourself. Takes about 45 minutes, costs about $1.00 to fix, and it's no big deal.
Apparently, pretty much any 2002 - 2010 big-body Ford, Lincoln, or Mercury uses this part and has the same problems about 4 years after you buy the car.
So I took off a piece of trim, undid (4) - 7mm screws from the front, unsnapped (2) electrical connectors, and screwed off (2) speed nuts and had the unit out of the car in 3 minutes. No kidding (3) THREE friggin minutes!
Took the unit into my shop, followed the directions exactly, replaced (4) 7 mm o-rings. lubricated them, put it all back together, and guess what. Factory air, just like a new car at the showroom. Total time, 35 minutes. Most of that time was spent reading the directions.
So thank you to the internets for giving me this gift.
The directions came from ( http://www.mercurymarauder.net/forums/showthread.php?t=36922 ) and were posted by some guy with a handle of JACook Senior Member, and he fixed my car.
$700, my aching ass.
Oh, same internets fixed my wife's dual-zoneAC problem on her Grand Prix. $39.95 for a new electronic vent controller, and it will freeze you out—the dealerwanted $650 to fix that.
What a bargain, I used Google(and using my wife's logic), I saved $1310.95 and fixed two auto AC's
Pretty cool, huh? Thankx Internets !!!!
**** Direction to Fix a Ford EATC Controller ****
Replacing the o-rings requires disassembly of the solenoids, but that's really not that hard to do if one hasreasonably good mechanical aptitude. But first, make sure they hold a vacuum when not energized. Connect a hose to the center vacuum port (where the black tube was connected) and suck it. It should hold a vacuum. If it doesn't, the following fix probably isn't for you. The solenoid assembly comes off the EATC module by unscrewing the two T-20 Torx screws on the back side of the module. Pivot the rear of the assembly up, and disengage the tabs at the front of the module. Disconnect the solenoid connector. Lay the solenoid assembly on itsback, and remove the 10 screws holding the solenoids and plenum strap to the plastic frame. At the wiring end of each solenoid, you'll see two metal tabs folded over that hold the solenoid coil and armature to the solenoid frame. Straighten these tabs, then carefully pull out the armature while watching to make sure you don't lose the spring or plunger inside. Note the o-ring on the armature. That's what we're after. Next, slide the coil off the end of the plenum tube, and then pinch the ends of the solenoid frame together to release it from the plenum. Once the solenoid is fully apart, fit the armature back into the end of the plenum tube to check that the O-ring has a good, snug fit. If it does, clean the inside of the tube and reassemble the solenoid. You can replace the o-ring if you like, but if it fits well, there'sno need. Make sure you pay attention to the screw flanges on the solenoid frame. Pinch the end of the frame together to fit it back onto the plenum. The spacer that goes at the plenum end of the solenoid has an undercut inside diameter and four grooves. The undercut end goes toward the plenum, and you'll see four ribs at the base of the plenum tube that mate with the four grooves in the spacer. The armature slides back on next, followed by the plunger, and then the spring. (The flat end of the plunger goes into the hole first, if you missed how it came out.) Use a bit of dielectric grease on the o-ring (I used Nylog), but do not use any oil or anything on the plunger. Make sure the tip of the armature, where the plunger seals against it, is clean and shiny. Don't get any dielectric grease on the armature tip. Clean and dry is what you want here. Slide the armature back into the end of the solenoid, and while pressing everything back together, fold the metal tabs back over. Repeat this for each of the four solenoids. On mine, the leaking one was the floor vent door (red hose). It was obvious when I got to that one. The armature came out much more easily than the others, and when I test-fitted it back into the plenum tube, it was a much looser fit. You might be tempted to replace only the O-ring on the leaking solenoidand leave it at that. Don't. (Guilty as charged, yer honor...) Do them all the first time, or you'll be back in there again.
Thankx for reading my rant!
bigmike
Visit my blog online at http://bigmikerant.blogspot.com/
I encourage you to leave your own comments or reactions to my rants (even if you don't agree with me) in the comments section on each post.
