1997 Crown Vic, base civilian car.
Daily Driver.
No modifications, runs great.
The headlights and tail lights stopped working.
Turn signals, brake lights, hazard flasher still function.
Reading online it looks like the light control module (LCM) is most lokely at fault. I sent my my LCM off for rebuild (new relays) and it was returned as the Potter & Brumfield VF4-11F13-Z06 and / or VKP-31F32-Z01 relays could not be found. OBSOLETE, no matches found. I emailed TE Connectivity ( Tyco/AMP) and got $35.00 per relay IF available. They are not in stock.
I bought a "remanufactured" LCM from Ebay that did not solve the problem, looked inside and the PCB was partially melted, no new relays had been installed and it was very dirty. I returned that.
I have checked all bulbs, checked all fuses inside and under the hood with multimeter, pulled and reinserted all fuses.
I bought a new headlight switch from Rockauto and installed it. No change. All dash lights and interior lights work.
I went to the local u-pull-it yard and pulled a clean multifunction switch and another LCM. Installed both but no change, no lights. Everthing else works.
My Autel MX808 scanner has trouble communicating with the car to get the VIN Number but when checking the LCM it says the LCM "passes".
Has anyone had and fixed this issue?
My next option is to install two toggle switches and power the headlights and tail lights with separate power leads.

 

Would you consider this?

There are times you can use a simple test light and times you should not.
This is one of the times you can and how about we start at the headlamp switch assy.
Do you have power there , if yes then it should be sending a request to the module. Is it? We need to know this.

Parking lamps and tail lamps are on the same circuit provided there is no separate module for front and separate module for the rear.
What I would do is run a separate wire from the positive post of the battery to any lamp up front and the same to the rear. If all the lamps work,no need to waste any time on lamps.
Before going any further, do we have power at the light sw assy?

 

I appreciate any help here.
I tested the two plugs on the back of the headlight switch.
On the black, 4x4 plug.
Key Off, Switch Off: there is power to the black wire/white stripe.
Looking at the back of the plug, locking tab UP, it is third from the left on the top row.
Key On, Switch Turned On for headlights- there is power to both the black /white stripe wire AND white/ purple stripe (might be brown stripe).
same as Parking Light position.
Large Gray Plug for Light Switch:
No power to any wire with ignition Off, headlight switch off.
With Ignition On, headlight Switch On the white/brown stripe wire is 12v.
Same as Parking position of the switch

I will jump a wire to a headlight bulb and see what happens.

Thanks fir the help. Let me try that.

 

There is something I find a little puzzling and that is why does the key have to be on for the headlamps to operate?

If I understand what you stated , that is the situation. Is this true?

 

Looking at my notes:
On the light switch, on the rectangular, 8-pin plug I have power to one pin (BRN/White with key OFF.
With Key On, I have power (12v) to two pins. The same pin as when the Key was Off and the pin with White/ Brown stripe ( might be Purple stripe as it is faded/dirty).
On the other plug to the light switch I get power to the White/ BRn wire with Key Off or Key On.

I will test it again and try the jumper to the headlights to see what that does tomorrow.
I don't think the key has to be on for the headlights to operate. I'm just testing the switch for power. The headlights don't work and the tail lights don't work at all but turn signals, interior lights, panel lights, and brake lights work .

I'm not sure about parking lights. They may turn on when I put on a jumper wire from the battery to the headlights.

Thanks,

 

I still believe there is a problem coming out of the headlamp sw.
This is why I believe this.
If the signal (power) coming out of the light sw goes to the front and rear for parking and tail lamps, if a module for one direction is not working,the other direction should work, but it is not happening. That power either is not coming out of the switch or there is a problem right after the switch.
Did you check ALL the fuses?

 

I pulled all fuses and reseated them. I then checked each side of the fuses for power with a multimeter. I pulled the circuit breakers and checked for continuity across the legs. I have other circuit breakers I can switch out. On the high power fuse box under the hood I pulled one relay then shifted all the others up one space to see if anything changed. No change. I pulled, checked, then tested each maxi fuse. All looked OK.
I bought a new Standard brand light switch from Rockauto and installed it. It lights up as did the old one with the light switch on.
I pulled a multifunction switch from a 1996 Mercury and switched it for the one in the car. No change. I will probably test the multifunction switch plug for power later.

I made a fused, switched jumper that plugs into the wiring harness. It is connected to the battery. I can flip the switch to turn on the low beam head lights. I guess I can repeat that jumper and switch combo for the tail lights, and high beams. I went to LKQ (pick-your-part) and pulled an LCM, fuses, little circuit breakers, multifunction switch, and wiring harness parts from a clean, not crashed, 1996 Mercury that is nicer than my car.
In checking the wire colors going to the tail lights I noticed the backup lights don't work.
I have a 1997 Ford Shop Manual and Electrical Manual for the car. The manuals cover Ford and Mercury cars. The manuals show wires connecting to the LCM but not exactly what the LCM does. The manual calls for special Ford tools for testing.
I assume each of the 5 relays control sections of the cars lighting. My Autel MX808 flashed all the lights I could see while sitting in the driver's seat. It then said the LCM "Passed".
I might open the other, used LCM from the parts yard and power each relay by the pins to see if each clicks/works. I'm not sure which relay of the five relays powers the headlights.
Four relays are
Potter & Brumfield VF4-11F13-Z06 (obsolete, not stocked)
One relay is a
Potter & Brumfield VKP-31F32-Z01 (obsolete, not stocked)
I assume the single relay VKP controls the lights but I'm not 100% sure. Most fixes shown on YouTube are of newer cars like 2003. Newer car LCM s have four relays.

Thanks for your help.