Ford Transit Upfitter Auxiliary Switches


Ford Transit Upfitter Auxiliary Switches

The Ford Transit can be ordered with the optional Upfitter Auxiliary Switches (Option Code 67C). Each switch is ignition supplied (they only works when the key is in “run” position) and can provide a 12V / 20A max output to an auxiliary load (such as an Air Lift Spring Kit Compressor, Exterior LED Bar, etc.).

So, you ordered the Upfitter Auxiliary Switches option and are ready to connect a load to it? NOT THAT FAST! You still have to order an additional accessory from the Ford dealer: The Wiring Pigtail Kit (Part Number WPT-1408). Without it, you don’t have access to the output of the switches:

Ford Motorcraft Wiring Pigtail Kit WPT-1408 for Upfitter Switches
WPT-1408 (EU2Z-14S411-XA)


Now, let’s get the driver seat out of the way because this is where that we access the switches output. There are four screws to remove; two in the back of the seat:



and two screws in the front of the seat:



Don’t take the seat off yet! We still have to detach the electrical harness:



We’re now going to take the batteries cover off. We have the dual batteries option; your setup might be different!

Remove those two screws to free the metal plate:



Here is the C33-H connector! We will connect our WPT-1408 pigtail to it.

C33-H Connector

While we’re here, if you ever blow one of the Upfitter Auxiliary Switch 20A fuse, this is where to replace it (see Fuse Panel in the picture above).

Note: Your C33-H connector might be buried under the other electrical cables, somewhere. Look carefully! Here is an extract from the BEMM (page 121). Item 4 is what you’re looking for:

BEMM C33-H and Fuse Panel Location



The WPT-1408 Wiring Pigtail kit comes with four crimp splices and shrink tubes, but we decided to install female quick-release terminal instead. This way, we can easily add or change the loads in the future:

WPT-1408 with female quick-release
WPT-1408 Wiring Pigtail Kit with female quick-release terminal


We can now connect the WPT-1408 Wiring Pigtail Kit into the C33-H connector:



Turn the ignition on and flip those switches up!

(you can use a multimeter to find out what switch power what wire…)






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You might be interested in this article (we’re using the upfitter auxiliary switch #1 to power it):

Air Lift 5000 Ultimate Air Springs Kit Installation


9 thoughts on “Ford Transit Upfitter Auxiliary Switches”

  1. I want to add a light bar in the recessed bumper step. Do I just run the positive to the pigtail and ground the negative to the frame? Do I need a relay?

  2. What are the specifications on the 2 auxiliary batteries you have on your van? I just purchased a 2018 that came with Aux batteries. I have a Dometic CFX75USW pluged in to the cig plug at the passenger rear door but they shut off after a short period of time. If any door is opened, the power comes back for some undetermined period of time.

    This is all very frustrating. Any idea of a solution for these batteries to run longer?


  3. FYI, the 2017.5 and newer Transits have the upfitter switch wiring connections behind and to the right of the glove box, kinda under the right cup holder. Pull out the panel under the cup holder, flop the glove box all the way down, and look around in there for a bundle (probably taped together) of about 20 wires. The thick wires are the ones you want; the owner’s manual says what colors to look for for what switch.

    Also, did you know the Transits have provisions for a cabin air filter, but come without? Access to the filter slot is directly behind the glove box. Takes 5 minutes (and no tools) to install.

    Part numbers:

    FORD 1839688
    FORD BK2118D543AA
    FORD BK2119G244AA
    CORTECO 80004650
    FRAM CF11743
    CORTECO CP1466
    BALDWIN PA30000

  4. Just a note…
    doing research to use these switched on our van for a light bar, we found that Ford changed the output locations for these switches with the 2017 model. For the later year, there is a C-33H for switches 3 and 4 (high power at 40A) behind the glove box in the dash. To get at switches 1 and 2 (these are still 20A), you need the ridiculously massive harness that “should” have come with all 2017+ that had the upfitters.

    …keep up the great work on the write-ups!

  5. Just stumbled accross your site! Thank you for sharing all this info! I am curious what you plan to connect to these switches. Thanks!


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