Here are the documents you can view to learn about the SEIC:
The following was originally posted by arcturner, I believe. It's the directions to do this setup:
You will need the following:
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 this photo:
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.
Also, the 2005 are the same as the 2006 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.
Using the first link I posted to Q108.pdf, that should give you everything you need to know, and the post I re-posted should sum everything up nicely on how to do it.