Retro-Fitting Power Seats Into a Crown Victoria P71

For this project, I'm going to be replacing changing out the seats in a Ford Crown Victoria.  The plan is to replace the police bucket seats with a split bench power seat from a similar car.  Not only are the replacement seats more comfortable, but this will add a third seat to the front, allowing the car to seat six people.

What Did You Make:  I purchased used seats from a 2001 Mercury Grand Marquis and retrofitted them into another car.  After removing them from the junkyard car, I soldered all the wiring together so I would be able to control the power seats and then put them into my 2000 Ford Crown Victoria.

How Did You Make It: The idea came along because there are six in my family.  While shopping for used cars, I found a Lincoln Town Car that had six seats, but when I decided to buy the police package Crown Victoria, it only had five.  When we had some minor trouble with the family vehicle, I decided to add a sixth seat to my car so we can use it as a spare.  My dad took me to the junkyard to get the seats, and my brother cleaned the new seats before I installed them.

Where Did You Make It: I worked on this primarily at home.  I went to the junkyard to get the seats, but actually did all the wiring and installed them at home on a Saturday afternoon.

What Did You Learn: The first thing that comes to mind when I'm asked this question is this:  Bring all the tools you need and then some.  I brought all the tools required to remove the manual seats from my car, but learned pretty quickly that the power seats have an extra rail in the back, meaning my socket wouldn't fit over it.  I also failed to bring a 12v battery, meaning I couldn't move the power seats forward to access the rear bolts.  That made my project considerably more difficult and more expensive - it took over 3 hours to remove the power seats and I had to spend quite a bit on a different wrench to remove the seat.  Everything worked out in the end, but my cost was almost double what I planned and it took three times as long.  All simply because failed to bring the proper tools with me.

Step 1: Getting the New Seats

The first step was to find out which seats will fit in the car without modification to the seat rails.  In my research I determined that any seat from a 1992-2011 Ford Crown Victoria, Mercury Grand Marquis, or Lincoln Town Car would bolt in, but you have to take certain things (like side airbags) into consideration if your car is a 2001 or newer model year. 

This site has any information you could ever want about swapping seats between a Panther-Platform car and was my primary resource during this project.

After I figured out which seats I could use, I started looking at the local salvage yards.  I found them at the third place we tried, the Nashville Pull-a-Part.

Step 2: Tools Required

To complete this project, you will need the following tools:

    12v Battery – Only required if you are removing power seats from a non working vehicle
    18mm combination wrench (ratcheting box wrench makes this a LOT easier)
    13mm 3/8″ drive socket
    18mm 3/8″ drive socket
    3/8″ ratchet
    Wire cutters
    Flat-Head screwdriver
    Penetrating Oil
    Soldering Iron
    Wire Stripper
    Electrical Tape
    Solder
    A few feet of wire
    Some wire nuts

Step 3: Removing the Seats

If the seats you're removing are manual seats, then this is made considerably easier.  Removing power seats is essentially the same process, but you will need a 12vdc battery to move the seats so you can access the bolts.

Before you start removing the bolts, you want to soak them with penetrating oil from the top and from underneath the car.  The last thing you want to do is break one of these off. (As a side note, I make my own penetrating oil.  It's just a 50/50 mixture of Automatic Transmission Fluid and Acetone.  The ATF is a good lubricant, and the acetone thins it out enough that the mixture can seep into the threads.  Then when the acetone evaporates, you can easily remove the bolts.  Works miracles on rusted bolts and is cheaper than almost anything you can buy at the store.)

After the penetrating oil has soaked in for a few minutes, slide the drivers seat all the way back and remove the front bolts with a 13mm socket.  Then you can slide the seat all the way forward to remove the rear bolts.  One will be 13mm and the other 18mm. 


If you have power seats and the car battery has been removed, this is how to move the power seat:

    -On the bottom of the seat, one of the red wires and one of the yellow wires will be the forward/reverse motor.
    -Cut the wires, leaving as much as you can still attached to the seat.
    -Connect +12vdc to one of the red wires, and connect the battery ground to the yellow wires.
    -Try the yellow wires one at a time, and one of them will make the seat move.
    -If it moves backward instead of forward, reverse the connection so the ground is connected to the red wire.
    -If the wrong part of the seat moves, try a different wire combination.  It WILL be one of the three red/yellow wire combinations.
    -If you have power seats, you will not be able to remove the 18mm bolt with a socket.  You'll need to use the combination wrench.

After the four bolts are removed, a manual seat can be lifted out.  If you have power seats, lean them back and cut the wiring harness as close to the floor as you can before pulling the seats out. 

Repeat the same process on the passenger side to remove that seat, then remove the seat control switches from the doors (if equipped).  Once again, leave as much wire attached to the switch as you can.

Step 4: Connecting the Wires (power Seat Only)

If you are putting in a manual seat, or if your car is pre-wired for a power seat, then you can skip this step.

After the seats were at home, I brought them inside out of the weather to wire the controls to the bottom.  Basically, just strip about 1/2″ insulation off of every wire under the seat, and the same off every wire from the controller.  The wires are all color-coded, so twist them together and solder.

NOTE: The black wire is ground, and the Black/White wire is power.  Twist these together, but don’t solder or tape.

After the wires are soldered together, tape them individually to prevent shorts then tape/tie them all into one bundle under the seat.

Step 5: Remove the Old Seats

This is what they look like with the controllers attached to them.  Alternately, you can put the controllers into the door panel like they would have been from the factory, but I didn't think it was worth the extra time/trouble.  If you choose to do this, you'll have to run extra wires through the door and do all the soldering while you're in the car.

Before you go to the next step, go ahead and remove the old seats from your car the same way you removed the seats from the junkyard car.

Step 6: Running New Power Wires in the Car

Now you'll need to run power to where the seats will go, if you are retrofitting the power seats into a car equipped with manual seats. 

I decided to tap into the cigarette lighter circuit for power, as it was already nearby.  Slide the cup holders out, and underneath you will see the wires.  The dark one is -12v, and the other is +12v.  Use a fishtape or similar to pull two wires from the front passenger seat mounting hole to the cupholder assembly, as shown in the picture.

Go ahead and splice the wires into the cigarette lighter power, keeping track of which one is positive and which one is ground.  I replaced the 20a fuse in slot #16 with one rated at 30a, to handle the extra current that will be running through this circuit.

Step 7: Put the Seats Into Place and Connect Power

Now put the driver seat into place.  Connect the power underneath using wire nuts (Blk/Wht is +12v, and Blk is -12v.) When you connect these, add another wire to each that is long enough to reach the passenger seat.  That’s how it’ll be powered.


Now you can install the four bolts, one on each corner to anchor the seat, then install the passenger seat in the same way.


NOTE:  Depending on what year your car is, and what seat the replacement came from, you may need to switch the seat belt mechanism.  This is easily done by removing the 18mm nut from the side of each seat and swapping the buckle from the old seat to the new one.


Here are some pictures of the underside of the seat.

Step 8: Replacing the Back Seat

I decided to go ahead and replace the back seat, simply because I knew that I would never find a matching back seat if I didn't get all of them from the same car.

This one's really simple to do.  Lift the bottom of the back seat up and it'll snap out of it's holder, then remove the two 18mm nuts on either side of the seat back.  They are the same bolts that hold the seat belt on.  After those nuts are removed, the back section slides upward and can be removed.

You can install the new seat just as easily, just reverse those steps:

Slide the back section of the seat down and into it's holders.
Put an 18mm nut on each side of the seat and tighten it.
Slide the bottom section of the seat in and push it down into the holders.

Step 9: Before and After Pictures

That's It!  I also wrote all this on my blog, which you can check out at www.source4school.com.

The old seats were all in fine condition, so they will be saved and re purposed later.  Not only is this good for me, but it's good for the environment since we kept all these parts out of the landfill.

This really is that simple.  Here are some pictures of the car, with the old seats and with the new ones installed.