Does Ford 'PreWire' for Options not Selected?

If I bought a Base XLT, would the wiring be there for the heated/cooled seats for example? I know some manufacturers standardize the wriing harnesses and just don't use what the vehicle was not spec'd for, and others have different harnesses based on trim level.

But since you can get an XLT with a the 202a package, was wondering if the wiring would be there already or not?

LRNAD90 said:

If I bought a Base XLT, would the wiring be there for the heated/cooled seats for example? I know some manufacturers standardize the wriing harnesses and just don't use what the vehicle was not spec'd for, and others have different harnesses based on trim level.

But since you can get an XLT with a the 202a package, was wondering if the wiring would be there already or not?

Click to expand...

Best answer, it depends. Seats are typically not wired in vehicles they aren't included, in my experience. I have seen heated mirror glass wired up to the door jam. I have seen the outside air temp wired up to the radiator. I have had the compass wired up to the A pillar. I have had to homerun wires for the keypad.
My 08 Mariner was wired for autolamps and only had to replace the HeadLamp switch. My 03 Taurus needed to homerun wires for the sunload sensor, and the HL switch. In addition to changing the headlight switch.

Buy a Ford wiring book or an official TIS dealership repair dvd from eBay. They contain crucial diagrams not freely available. Like connector, splice, and ground location maps. They also contain connector pinouts that people don't upload when they publish the schematics.

Your best bet is to pull out the seat and check under the rug. If that is not feasible, check the fuse block.

My workflow is check for the fuse. If it's there look for the wires in a connector that is in circuit.

The seat doesn't usually have a spur harness. It's usually in main body harness that every other harness plugs into to get to the target device.

However, that doesn't mean that your wires are there. Ford could make multiple body harnesses.

You used to be able to visit Fordparts.Com. Search for your body harnesses. The part number of the main body harness is 14405. Check if there is a varient with and with out heated seats. However, that's not working since the first redesigned the site.

Sent from my SM-N950U using Tapatalk

Thesavo is 100% correct in his advice. My experience with the 3rd Generation cars is that Ford has two main harness selections: One for the base cars, XLT and SSV and one for the Bauer and Limiteds. The base harness lacks connections for steering wheel remote radio, sub woofer. There are fuses in the fuse box, but no output pins, which you can add along with the wiring.

Savo says "it depends," and he's right on. You never really know what harness was used in which car until you look. Lots of parts were interchanged subject to availability or the ordered options.

As said above, the only true way to see what you have is to pull off the trim and look. But you need a good wiring diagram with connector illustrations and locations. It's a bit of work updating a base model for accessories, but with the right information, connector pins and tools, along with neat work and the knowledge to read the diagrams, you can do a great job.

YES, the wiring IS THERE for the seats. I know because before I bought mine, I had them price a XLT and furnish me the seats...they told me the leads are part of the wiring harness as are tucked under the carpet.

jeff

jeff kushner said:

YES, the wiring IS THERE for the seats. I know because before I bought mine, I had them price a XLT and furnish me the seats...they told me the leads are part of the wiring harness as are tucked under the carpet.

jeff

Click to expand...

They're you go. If you are planning on any wiring work, you should invest in the wiring guide for the your model year.

@jeff are there any variances to worry about? Has Ford done any connector or pinout changes the original poster would have to worry about?

Sent from my SM-N950U using Tapatalk

I'm afraid the answer, in general, is "NO." But, in some cases, it's "MAYBE."

As much as possible, Ford tries not to include wiring that's not needed because it costs more money. Then again, it's also expensive to design, make and stock many different harnesses and sub-harnesses for multiple options. Thus, they will try to consolidate as much as they can. This is why I believe the 202A package became available on base XLT models starting in 2015. It was a way of consolidating wiring in order to save money.

One thing I know for sure is the wiring for the rain-sensing wipers is not included in XLT trucks. It's a separate sub-harness. I am in the process of adding that option and I found this out the hard way.

If your ultimate goal is to add heated/cooled seats, you are in for a long and difficult journey. When I bought my old 2009 XLT with cloth seats, I thought I could upgrade so I got some seats from a 2010 Navigator. After obtaining the wiring diagrams (something I should have done *first*) I discovered there is no direct connection between the heated/cooled seat control buttons and the seats themselves. It's all done via computer modules over the vehicle network.

Not only did I need to solve the mystery of how to add the buttons (since I had manual climate control), there were also two new modules needed that my truck didn't have, plus there was also the potential that several other modules might need to be reprogrammed in order to make it all work. The result of all this is I still have those beautiful seats in storage and they never made it into my truck.

Bottom line: While it's theoretically possible to upgrade to memory/heated/cooled seats, it requires some computer "hacking" in order to make it work. Yes, thanks to FORScan we have more tools available today to assist in this sort of thing. But, as far as I am aware, no one has ever successfully done this upgrade in an Expedition.

Wouldn't the "cooling" feature require some sort of duct work? Where does that cooled air come from?

2009+ models use a TED unit (Thermo-Electric Device) patented by Gentherm. Passing electricity through it in one direction produces heat, reversing the flow produces cold. These are controlled by electronic modules. Electric cooling fans and ducting distribute the air through the perforated leather inserts. Channels in the seat foam are required to make it work. As the seat ages and with use, the seat foam crumbles and the air channels get blocked, reducing the effect.

You can also have these installed aftermarket by an authorized Gentherm dealer. But, it's expensive!

@LRNAD. What model year? 2017?

Sent from my SM-N950U using Tapatalk

I have the electrical manual for the 2016 Expedition, I would expect the 17 to be very very close to it.

The electrical Manual alone is as thick as a service manual!

Jeff