Is it possible to convert my 2 bulb tail light to 4 bulb, by just switching the harness? i bought a set of taillights today and got the harness with it. would it be doable or would i have to modify to make it work?

well turns out i would have to do some wiring to get what i want. i did noticed that the harness i got has 4 wires instead of 3, i read i have to wire some stuff up from the driver side kick panel. is it possible to to bring a certain lead to make it adaptable?

connetions (left - current one in use / right - 4 bulb harness)


complete harness

IIRC it works kinda but has the side effect of the light being worse since the power isn't enough to make full use of 4 bulbs.

It depends what you want it to do. If you want proper 4 bulb tails you need to split the brake signal before it goes to the multi- function switch and run the extra wire all the way back. A stock 4 bulb has two park/stop lamps on top and two dedicated turns on the bottom.

If you just want to double the amount of bulbs then you need to splice your pigtails. As Nomad said that would reduce the output of your stop and turn signal lights at the expense of more bulbs. This hack will give you all 4 stop/turn and keep 2 park lamps on top.

Think about what you want it to do and then I'll try to talk you through it further. Basically if you want to separate the brake/ turn signal it needs to happen before the MFS, otherwise they will stay integrated.

i want it to function like a normal crown vic, not like a p71 , i like to have my turn signals seperated from my stop lights. im good at wiring, just need to know more info to were to go.

Then you need to find the brake signal input on the multifunction switch and unpin it, or cut it. It should be a light green wire. Use a test light to verify you're getting a brake signal when depressing the pedal. There are several connectors so make sure you check it and have the right one.

Once you find it, run a wire from that end to your trunk connector and again match it up with the light green pin on your new harness. You may want to obtain the mating chassis side connectors to your new 4 wire harnesses, and repin the chassis side harness, along with the new brake wire. Or, repin the old 3 wire connector on the bulb harness and hardwire the green brake lead. It just depends how clean you want to make it. But make sure orange goes to orange and brown to brown, black to black. The wire you run, whatever color, goes to green on both ends.

Then put your bulbs in and check it with a friend. It should be good to go - park/ stop on top, two turns on bottom.

little off topic but i like your DUBS!!!!

hope this isn't hijacking: any way to upgrade to 4 bulbs from 2 and not lose light output to all 4 bulbs? Or is the only option LEDs?

prodigalson, I want to do to my 2008 CVPI what tx2000p71 is doing: that is, to have the two stop and tail in the upper red area and the turns in the amber. I have retrofitted the four lamp harnesses and the appropriate connector in the trunk. I have run a green #16 wire from the LH kick panel area to the trunk.
The brake signal input wire to the MFS appears to be at connector C202A-4. It is a green wire with red tracer. I follow your instructions to cut this wire. I would re-splice it with male/female bullet connectors to facilitate restoration of the two-lamp configuration if needed.
Now I read your instruction and do not understand if my new green wire needs to be connected to the end of the cut wire from the MFS or the end from the brake position switch. I assume the latter, but want to make sure.
Thanks.

Since you already cut the wire at the MFS C202a-4, it does not matter where you tap the new wire. You can go from that end or directly from the position switch. It is the same signal, just a longer length of wire.

You only need to cut it to interrupt the brake signal to the MFS, which you did. Otherwise your brake signal would still be coming out of the turn lamps, which it won't because you already cut the wire. Splice it in where you like and it should work.

Prodigalson, your advice was quite on the mark. I choose to cut and reconnect the brake signal wire near connector C211-5 inside the driver's side kick panel. I now have "retail-look" signals like the LX CV's.
I had already installed four-lamp housings with bright trim and four-wire sockets from a salvage source. I do not think the four-wire sockets/harnesses are available any longer from Ford.
I appreciate your clear explanation and help.

I'm glad it worked for you!

I resurrect this topic because I need to change the 2 bulb tail light to 4 bulb.

What I understand of all the information is that the braking signal goes from the pedal switch to the fuse box in the dash. From there, it goes in the harness to the multifunction switch where it is combined with the turning signal. Then, it goes to the LCM and finally, from the LCM goes to the kick panel, where it is connected to the harness that goes to the tail lights. Is it correct this?

My target is instead of cutting the cable, I want to create a male/female pair of connectors before the multifunction switch, where the input brake signal is re-drive to a cable to the tail lights. What is the reference part for the connector on the multifunction switch that has the brake input signal? Is there a female part for this connector and what is the part number?

Thank you for your help

The wiring routing you speak of sounds about right.

For the MFS pinout, Idk if the attachment will help. It's for '09.

It looks like anywhere the brake wiring is involved at the MFS, it deals with pins 2, 4, 5, 9, & 10. I think brake signal input is pin 4.

The connections at the MFS are referenced as 202A & 202C. Female connectors 202A & 202C most likely have call out # of 14401. I don't know the prefix or suffix.

Thank you for the answer. I really appreciate it.

I am reading about the routing and the unique point that I am not sure is if first the brake signal goes to the LCM and later to the MFS or is viceversa. I was checking the cable in my car and because it is the same harness including with the fuse box I cannot tell. Can you check what it is the correct route?

Anyway the more secure way is made the modification in the MFS. I have located the connectors 202A, 202B and 202C in eBay. However I couldn't find the 14401. Maybe I have to call to the dealer on Monday (today, parts is close).

On the other hand, if I don't have enough room in the dash and the signal firstly goes to the LCM, do you know the connector male/female in the LCM?

Thank you.

Below are 2 diagrams of Brake Pedal Position Switch, & MFS. They are for '08 Crown Victoria though. I couldn't find '09.

The brake signal wire (LG/RD) goes from pin 1 Brake Pedal Position Switch directly to pin 4 of MFS.

I think I found Ford part numbers for the 202 connectors...

I believe MFS 10-pin connector 202A is 3U2Z-14S411-RJA.

I believe MFS 12-pin connector 202C is 9U2Z-14S411-ZA, with Motorcraft equivalent WPT-1047.

I can't find a part # for LCM connector, but I believe the connector reference # is C2145B; however, I don't believe you need to do anything with wiring to the LCM.

The # 14401 turns out to be a reference # for the harness, not the connector. So, disregard it.

I helped a member do the 4 to 2 conversion before. It was for an '03 though. I'm wondering if all you'd have to do is the opposite of what he did, since you want 2 to 4.

His conversion involved changing position of wires at kick panel connector which re-routed brake signal. What he did was make his wiring like yours is already. I'd think if you did reverse steps, you'd get the wiring he had to begin with, which was for 4. That's if you have the extra bulb sockets/wiring for the rear...

Is that what you're doing? Are you going from 2-lamp red to 4-lamp red/amber, or something else?

If you need wiring diagrams of rear 2-lamp, & rear 4-lamp configurations, I have them. I'll hold off on those for now. I don't want to confuse things.

I really appreciate your detailed explanation. I finally decided to go for a simple route. I purchased the connector C211 and I am doing an interface that connects with the male/female C211 connectors in the car. All the connectors are paired except the pin number 5, that I didn't paired. The conector 5 brings the breaking signal to the MFS. Instead, I will run a wire from this part to the back, where I will connect the 4 bulb harness. it can also be done cutting the light green with red tracer wire after the female C211 conector in the harness 14401, and wiring from this point to the back a cable.

^ Hope it goes well! Let us all know how it works out.

I am working on the rear lights and it looks like that it works. I will try to post a full guide when I completly check that it works properly.

Digging out this old thread... any chance any one could repost the pictures of the connectors and the "2009 victoria MFS pinout.jpg"?

As far as I understood I need to get directly to the MFS below the steering wheel?

You don't need to cut the wire directly at the MFS itself, you just need to cut the wire between the brake switch and MFS. It passes through the connector behind driver side kick panel (where the E-Brake is).
For your year it's a green/red wire, I'll look up the exact pin position later.
By cutting this wire, your existing bulbs will now work for turn Signal only, no brakes.

Take the car body side of the wire you cut (not the side going to dash) and splice into it, run it all the way to the tail lights. This is your new brake light feed for your new bulbs.

Thanks,

found 3 green/red cables in the connector under the kick panel. 2 of those have a brake light signal :-/

So i just opened the stering wheel cover and pinned out the green / red cable directly at the MFS. I will upload pictures later ;-)