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Discussion Starter #1
I did my first LCM repair on an 05 Crown Vic for about $20 and that included shipping charges. Mouser.com sells the exact same relays that go bad in your LCM for under $4 a piece. Mouser is fast too. I ordered Friday and had my relays by Monday. The part number for the relay is EQ1-11111S.

If you have some soldering skills, just replace all four of those relays and put your LCM back in the car. I don't have a schematic to isolate which relay does what. But considering I salvaged a $500 LCM for less than $20, there's not much reason not to be proactive and replace all four.

happy happy:priest:
 

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I'm the Doctor.
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It can be 'fixed' even cheaper, and without removing the LCM itself, but you lose some level of functionality in the process.. It involves de-pinning the LCM plugs a bit, using an insulation splitter, and utilizing bits of wire to have two external relays. I only know this because my car currently runs this setup, until I either have the money for new relays that I can install inside my LCM, or figure out a better solution.

If you think your LCM relay replacement is impressive to you... try the headlight relay and wiring upgrade. It gets pricey, upwards of $50 if you have to buy all of the wire, shrink tubing, crimp and heat spades/terminals, and wire conduit... but the relays are $6/ea. from Radio Shack.

The upgrade is well worth the money, however. We all are aware of just how bad the Crown Victoria's headlights perform... this modification that effectively says 'To hell with you, factory wiring harness!', is monumentally brighter.
 

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Discussion Starter #4
Im not concerned about modding the LCM's considering how cheap my current fix is. I've been thinking that perhaps most LCM woes come from those who have retired P71 Vics and if that's the case, I definitely can't fault the original relays for failing given their work life. I'd love to see some feedback from members who have replaced or repaired their LCM's and what I would like to know specifically is whether or not your Vic was ever used as a police or other fleet vehicle before you bought it. I'd also like to know some ballpark figure as to how many miles were on your car when the LCM did fail. For what I've seen on my taxis so far, the original LCM relays will typically fail anywhere between 125 and 140K. How did your Vic do?
 

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Im not concerned about modding the LCM's considering how cheap my current fix is. I've been thinking that perhaps most LCM woes come from those who have retired P71 Vics and if that's the case, I definitely can't fault the original relays for failing given their work life. I'd love to see some feedback from members who have replaced or repaired their LCM's and what I would like to know specifically is whether or not your Vic was ever used as a police or other fleet vehicle before you bought it. I'd also like to know some ballpark figure as to how many miles were on your car when the LCM did fail. For what I've seen on my taxis so far, the original LCM relays will typically fail anywhere between 125 and 140K. How did your Vic do?

I have a 2003 Mercury Grand Marquis and my LCM started failing at 69K miles, so I think that pretty much rules out any effect law enforcement use has on the problem.

Currently I am trying to figure out what to buy to put my headlights on external relays after I fix the LCM. The LCM internal relays will continue to blow if the load isn't relocated.
 

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Discussion Starter #8
Thanks for your input Andrew. However, I think Bert is right on the money. I've done 5 LCM repairs now and I've noticed consistently that the circuit paths on the boards showed discoloration from being overheated. The overheating happens when the relays are soldered in at the factory and all the LCM's showed the discoloration before I ever soldered in new relays. (not that I didn't burn one or two myself on the first try.) I would think it's entirely possible the overheated soldering is shortening the life span of the relays since the problem isn't P71 or fleet specific. Click on the thumbnail below and you can see how two of the circuit paths are browned out under the relay on the right side.
 

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I just finished the repair on my LCM tonight. Direct replacement with a new EQ1 relay from mouser. First time I've ever done it, and I have minimal electronics experience. Plugged the LCM back in and everything seems to be working perfectly. Hope it lasts!
 

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Discussion Starter #11
As long as your solder joints turned out shiny without too much or too little solder, you should be fine. Shiny solder with a concave radius means your heat was good and you didn't use too much solder. If your solder cooled to a dull finish and balled up or gobbed up, you didn't get the joints hot enough. If the LCM fails again in a short period of time, recheck or resolder the solder joints. I hope you got it right and your LCM leaves you lit up the right way for a few more years.
 

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Discussion Starter #13
The LCM is a Lighting Control Module. All your lighting functions in the crown vics, maurauders, and grand marquis' are controlled by this computer except perhaps the hood and trunk lights.

They've been known to have all kinds of lighting failure symptoms due to defective relays. It's a very common problem and a very costly problem to boot. An LCM typically runs $300-$500 for an OEM replacement and they're becoming more and more available in the aftermarket. NAPA was offering remanufactured units for around $260 and you can find repair services on eBay for around $100. Some are offering lower prices for their services, but you get what you pay for. Pioneer wheel and rim of Madison was offering Cardone remanufactured LCMs to us at my cab company for about $156 with a core charge.

Potentially any lighting failure in these cars can be attributed to relay failures in the LCMs including headlights, side markers, turn signals, hazard flashers, brake lights, and on and on. Occasionally, a faulty multifunction switch can cause headlight failures (usually high beams) and a common break in the wiring going to the LCM is sometimes responsible for brake light failures instead of the LCM itself.

That should provide everything you need to know in terms of basic LCM knowledge. The rest has probably already been dealt with in earlier posts on this thread and other threads for external relay modifications to LCMs.
 

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Thanks no common sense, I really appreciate the info. I've got a creme-puff with nothing wrong but I want to know all about potential problems like these so that I am prepared. Thx again. -Brian-
 

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Im not concerned about modding the LCM's considering how cheap my current fix is. I've been thinking that perhaps most LCM woes come from those who have retired P71 Vics and if that's the case, I definitely can't fault the original relays for failing given their work life. I'd love to see some feedback from members who have replaced or repaired their LCM's and what I would like to know specifically is whether or not your Vic was ever used as a police or other fleet vehicle before you bought it. I'd also like to know some ballpark figure as to how many miles were on your car when the LCM did fail. For what I've seen on my taxis so far, the original LCM relays will typically fail anywhere between 125 and 140K. How did your Vic do?
My suspicion is that these tiny relays (slightly larger than a sugar cube) are engineered for only a certain amount of power, and that overload conditions may be causing them to fail. Overloads can be easily caused when salt-laden moisture gets into the connectors, for those of you that live in an area where salt is put on the roads. My CV has 155,000km on it and it's a cream puff having been babied since new; but, I run high wattage lights that are 80W low beam and 100W high beam (sorry, only available in Canada). With all the winter/night-time driving I do, I think it finally failed, possibly from running 200W in a circuit designed for 130W. My auxiliary lights (100W LightForce) are controlled by a relay, and if I were going to do anything different, I would have also put my OEM high beams also on a relay to protect the LCM.

That being said, I can appreciate being able to get an identical replacement relay and installing it, but why would you do it? From another forum I saw how a guy unsoldered the damaged relay, and pushed/soldered wires into the PC board in its place, and that's what we did yesterday. My friend held the tip of the soldering gun on one side of the board, and I held and pushed the tinned wire through from the other side the second it was hot enough.

You only need four wires, two for the primary side and two for the secondary, and I cut them 6-8 inches long, crimped on female spade ends, and then attached them to the appropriate legs of a Bosch relay. There was a hole large enough on the side of the LCM to conveniently run the wires through, too. We plugged everything in to test it and it worked great, so I buttoned it all up and reinstalled the LCM.

I doubt that Bosch relay will every fail, but if it does, it is now easily accessible outside the LCM. Hope this helps, and Happy New Year!
 

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Discussion Starter #16
I can appreciate being able to get an identical replacement relay and installing it, but why would you do it?
I don't see the point in performing the external mod when it takes years for the relays to fail to begin with...especially knowing how cheap the replacement relays are. With the recent practice I've been afforded lately, the repair time is about an hour from the time I pull the LCM to the time I reinstall it. More importantly for me is that all my LCM repairs are devoted to a fleet of very busy taxis. The mod would be inneficient from a time standpoint in creating and routing the extra wiring for all four of the relays. Then account for the space the extra relays would consume under an already crowded dash. We don't have as much hardware as the state patrol used to shovel into these cars, but we still have our fair share of extra wiring and hardware for radios, fare meters, and GPS. Since we only run our cabs on a three year cycle before we retire them, we'll likely never see the LCM's fail a second time. Before I found the relays and learned how to solder them in, we replaced our LCM's with new OE units and maybe once had a repeat failure in that cab.
 

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I hope that I'm not hijacking anyone's thread, but this is also LCM related. My '01 GM's (98,000 miles) turn signals blink erratically (both directions) only when the A/C blower is on high. All other LCM related functions are normal. I have checked battery and alt voltage, both normal, and I have cleaned all turn signal bulbs and connections, no corrosion was present. I do not see a relay in the LCM schematic that controls the turn signal function. Any thoughts?
 

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Hello Bert:
Thanks for the tip, I'll give it a try. I've had the bulbs out, (front and rear) there was no corrosion, but the bulbs are ten years old. Does bulb resistance increase with age?
GQ
 
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