Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Upfitter Switch wiring

  1. #1
    Junior Member
    Join Date
    Aug 2008

    Question Upfitter Switch wiring

    Brand newbie to this forum, looked on FAQ and nothing seen on this topic - thought that was strange but I'll ask and gladly take the heat if this has been answered thousands of time already. Just point me in the right direction to find the answer please ... 7 month-old F350 4x4 single - diesel

    I ordered the upfitter switch package -- the manual tells all about the wires terminated in pigtails inside the cab, presumably under the lower dash panel.

    Question: what do I need to do to get the wires outside the cab/dash area in order to add lights or other accessories to the outside of the truck?

    Is there a recommended firewall pass-through? Wire routing?
    Should I mount a terminal block under the dash panel or are the switch output wires long enough to terminate in the engine compartment?
    (Not that I see much room in there with the diesel and the two batteries etc) ... Do folks usually handle it by a terminal block in the engine compartment?

    Thanks for any insights you might provide.
    Paul --

  2. #2
    Platinum Member
    mudseeker's Avatar
    Join Date
    Feb 2006
    there was a post about this a few months ago, give me a minute to see if i can find it.

    ps: to the forum.

    here you go, hope this helps.
    2005 f350 uploader dash switches
    <----just your average 5.3

  3. #3
    Senior Member tjzz4's Avatar
    Join Date
    Oct 2007

  4. #4
    Junior Member
    Join Date
    Aug 2008

    Question Thanks, but I need just a bit more

    Thanks to the responders, on the upfitter switch questons, I do appreciate this. I still have yet to figure out how to route the switched output wires outside the cab of my 2008 F350 4x4 ...

    The docs clearly show the switched-output pigtails in a bundle underneath and behind the dash panels. OK, so I now need to route them outside of the cab so's I can power up some accessories -- lights or winch or whatever.
    Has anybody reading this forum done this?
    I am thinking I need to:
    1. find a place to mount a terminal strip near the pigtail bundle under the dash as these pigtails look rather short in length

    2. Find a way to route wires through the firewall - is there some sort of penetration there, already, that I can just take a rubber plug out of?

    If there exists no usable penetration, what do folks do to get the wires out of the cab? Should I drill a hole in the firewall?
    If so, where?

    3. Mount another terminal strip in the engine compartment -- where?

    Like to hear some advice or anecdotes -- thanks.

  5. #5
    Senior Member
    75K30's Avatar
    Join Date
    Jul 2006
    For 2008, you have existing pass through wires, and you have upfitter wires. These pass through the firewall just above the master cylinder on the driver side.
    I will have to get a book out to determine the wire color. I believe these changed for 2008. This is a very simple upgrade.
    I have info for the 05 to current truck (if that helps) but I do believe there were small changes for the 08.

  6. #6
    Senior Member
    75K30's Avatar
    Join Date
    Jul 2006
    Mud was looking for an article I shared a while ago. Here it is again. I know it does not cover the 08 exactly, but does give you an idea of how easy it is. Be easy On my dry humor. Lol.

    1ea - 2005 Ford Truck
    2ea - red butt connectors (or solder & tape)
    1ea - available UpFitter switch (although any 12v switched source will do)
    1ea - access to this forum
    1ea - crimping tool
    1ea - long nose pliers
    6" - stranded hook-up wire (14-16 ga)
    11 mm - socket
    1ea - ratchet for socket
    1ea - ability to follow directions


    1ea - garage large enough to enclose the truck (especially when raining)
    1 to 6 - 12 oz refreshments
    1 - Ford Tough tatoo
    1ea - Electrical Engineering Degree
    1pr - non-conductive footwear


    Remove all rings, watches, & bracelets (a must when doing electronics)
    Remove the drivers side access panel (below the steering wheel)
    Using the 11mm socket & ratchet, remove the 4 bolts which hold the fuse panel. Gently, pull the fuse box through the opening and leave it hang.
    Look for the UpFitter wire bundle as noted in manual.

    Choose which switch you want to use. I used Aux-4 as it is one of the 10 amp circuits and only a signal voltage is required. Here is a list of wires:
    Aux-1 Circuit No 1936 wire color: Orange/Lt. Green [30amp]
    Aux-2 Circuit No 1933 wire color: Orange [30amp]
    Aux-3 Circuit No 1934 wire color: Orange/Yellow [10amp]
    Aux-4 Circuit No 1935 wire color: Orange/Lt. Blue [10amp]

    Pull the black end off the chosen wire and strip off 1/4" of the insulation.
    Crimp one end of one butt connector to this wire.
    Prepare the 6" wire by stripping 1/4" of the insulation off both ends.
    Crimp one end of the 6" wire to the open end of the butt connector used above.
    Crimp another butt connector to the other end of the 6" wire.
    Locate the top of the parking brake pedal (approximately 6" below the AUX wires).
    Locate the SEIC/CASC wire bundle (about 12 wires with black ends)

    Locate the solid ORANGE wire. There are many orange wires in this bundle, but most have a color tracer. You must use the SOLID orange wire.
    Pull the black end off the SOLID ORANGE wire and strip off 1/4" of the insulation.
    Insert the SOLID ORANGE wire into the open end of the butt connector attached to the 6" hookup wire.
    This completes the electrical portion of this project. You need to replace the fuse box and access cover.


    All the following are required to enable high idle:

    Parking brake applied.
    Foot off of service brake.
    Vehicle in PARK (automatic trans.)
    Foot off of clutch (manual trans.)
    Foot off of accelerator pedal
    Vehicle speed is 0 mph (stationary)
    Brake lights functional
    Engine at a stable base idle speed

    Start your engine! Flip the UpFitter switch. The engine will idle up to 1200 rpm. If any of the required items changes state, the engine will go to its normal idle speed. If the item state is changed back to the required state, the idle will return to 1200 within 3 seconds.

    Happy Hi-Idling!

    Also, the 2005 are the same as the 2006/7 models, at least for the SEIC setup. Also, you can use the orange PTO wire, or you can use the purple/light green charge protect circuit wire. That one will vary the idle from 1200-2400 depending on current draw, in order to keep the battery charged properly. Some have noticed that their RPMs will creep up and up all the way to 2400, slowly, even when the current draw is staying steady. The orange wire locks up the torque converter on the tranny, I believe, but stays at 1200. With the orange, you can also wire in a resistor to make the idle stay anywhere from 1200-2400, and it will stay there and not vary, using the resistor. Also, with a manual tranny, the resistor is required.

    Yes this is probably way more than required, but it was eaasier to include everything.
    I will look for 08 specifics.

  7. #7
    Senior Member
    75K30's Avatar
    Join Date
    Jul 2006
    Alright I found the SVE bulliten for the 08.
    Little extra reading, and just in case you do not want to wire the SEIC option, this does describe the wires needed to wire your upfitters.
    This should help out. I will condense this, and create another, easier to read article, but this should get you going.

  8. #8
    Junior Member
    Join Date
    Aug 2008

    Great info, need a bit more

    Thanks 75K for this info.
    I am, however, still unclear about how to go about what I am trying to do.

    While it is good to know how to achieve a higher stationary idle, this was not my first goal for using the upfitter switches. I just wanted to put some additional lights on the bumper guard and maybe mount a winch.

    So you refer to an existing wire bundle in which to look for the solid orange wire with which to regulate a higher idle speed. OK, I'll keep that in mind for doing, when I find myself a need to do so. Good stuff to know.

    Are there other wires in that bundle that are unused, and unterminated, (both ends presumably) which are part of the wires which pass through the firewall?

    I've tried to make my questions clear, but it seems that they are somehow not.

    I just want to wire up some accessories: lights, winch etc. to the outside of the truck, and wish to use the upfitter switches to operate/power these accessories. I presumed from the get-go that this was one of the primary uses of these switches.

    The upfitter switch output side wires are <stubbed out/pigtailed> inside the cab, and I need to get these wired to outside accessories.

    There seems no suggestion in the Ford docs about how one goes about routing these wires to the outside of the cab. I am only guessing that the best way to do this is through the firewall, but I may be completely off base here.

    Has anyone used the upfitter switches to power outside accessories?
    If so, how did you route the wires to those accessories from the pigtails under the dash?

    Thanks, Paul --

  9. #9
    Junior Member
    Join Date
    Aug 2008

    the info is in the SVE 75K sent with his post.
    There are four 'pass-through" wires noted there.
    Pity they didn't leave either the switched pigtails or these pass-throughs a bit longer, so they could be long enough to directly connect together with a butt-splice rather than having to add another 6" wire and a second butt-splice.
    OK, I think I've got it now. I may add the two terminal blocks: one in the under-dash area, and one in the engine compartment, and if I do, I will send some pics back in to the forum. Thanks for all. Paul

  10. #10
    Senior Member
    75K30's Avatar
    Join Date
    Jul 2006
    Alright, you saw the link to the SVE. This SVE does show where the wires are located, and provides a fairly detailed description.
    WHile I can appreciate your direct question, and often in my (as well as others responses) details above and beyond are provided. This is performed to enhance our search function. This site grows as a result of an individual searching the internet, and ending up here. Our existing members can easily refer back to threads such as this when the term "upfitter switch" is used as a keyword.

    I am glad you found a little bit of information to help you make up your "terminations" and it is unfortunate that you have to add wire, and even perhaps a terminal block or two.
    On my 07, this was not the issue, but I did wire an interposing relay (in series) for higher amperage applications.
    Just by your use of some terminology, I trust you are not new to electricity, and this should have been a fairly easy project for you.
    Pics of the 08 would be helpful for future use.

Page 1 of 2 12 LastLast

Similar Threads

  1. Wiring diagram?
    By mwalton777 in forum Chevy Truck Forum
    Replies: 9
    Last Post: 12-28-2007, 06:22 PM
  2. GMC Sierra Wiring
    By ragnar in forum GMC Truck Forum
    Replies: 3
    Last Post: 10-15-2007, 09:11 AM
  3. Towing wiring
    By TravelinSierra in forum GMC Truck Forum
    Replies: 6
    Last Post: 01-05-2007, 07:41 AM
  4. S10/Sonoma re-wiring
    By eaclark in forum GMC Truck Forum
    Replies: 1
    Last Post: 10-05-2006, 01:22 AM
  5. Need Wiring Help
    By bmoyce1 in forum Chevy Truck Forum
    Replies: 1
    Last Post: 09-11-2006, 07:34 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts