This is the easy step-by-step instructions to set up your '05 or '06 Super Duty to have a high idle option. This is for diesel trucks with the factory auxiliary upfitter switches. This procedure replaces the need in the older trucks to buy an AIC (Auxiliary Idle Control) module from Ford.

Refer here for pictures.

Tools needed:

Parts:

One butt connector for 18ga wire

How to do it:

• Pull the full panel cover off. It's the big panel just below the steering wheel. The top just pulls out from the dash and then swings down to let the bottom catches come free.
• Remove the 4 bolts (10mm heads) that hold the fuse panel in place. Pull it out and let it hang down.
• Find the upfitter switch you want to use (see picture above for location).
• Find the SEIC or BCP wire you want to use (same picture above).
• Strip the end of each wire 1/4" and crimp the butt connect on them to connect them together.
• Put the fuse panel back in place and reinstall the bolts.
• Snap the fuse cover back in place.
• Drink beer. (Very Important Step!)

SEIC or BCP Wire?

You can hook the switch to either of these wires to achieve high idle. However, they each have slightly different behaviors. If you're doing this mod to help keep the AC cold or the heater hot, or keep the revs up when jumpstarting somebody, then you probably want to use the BCP (Battery Charge Protect) wire. If you're doing this mod to use the PTO (Power Take-Off on your transmission), then you probably want to use the SEIC (Stationary Elevated Idle Control) wire.

If you want to hook up to the BCP wire, find the purple wire with the light green stripe in the bundle just near the top of the emergency brake pedal. Note: don't be fooled into using the light green wire with the purple stripe. That's the output wire for a BCP indicator lamp.

If you want to hook up to the PTO wire, find the solid orange wire in that same bundle (near the e-brake).

Differences in behavior:

• will automatically vary RPMs from 1200 up to 2400 to maintain battery charge
• does not lock the torque converter
• has an additional wire that is an output that can be used to turn on an indicator lamp to show that BCP is active. i.e. if you want to install an LED in your dash to tell you BCP is on. Since the upfitter switch has a light on the end of this, I don't see much point in this (if you're using a factory upfitter switch).

• does not automatically vary the RPMs. Sets idle at 1200 (unless you take advantage of the additional control wire).
• has an additional control wire that you can hook to a resistor to vary the RPMs. You could install a variable potentiometer (i.e. a knob on your dash) to let you dial in whatever RPM you want, when SEIC is active - from 1200 to 2400 (I think that's the max).
• locks the torque converter

Which Upfitter Wire to Use:

There is a bundle of 4 wires. They are just behind the top of the fuse panel. They're all orange, with different colored stripes. They are:

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]

The high idle circuit needs minimal current, so you may as well use Aux-3 or Aux-4 and save the high current switches for something that needs it.

Final Notes:

By far, the hardest part of this (for me, anyway), is actually stripping the wires and crimping on the butt connector. There just ain't that much room on there to fit hands and tools. It would probably be a lot easier if you used a short piece of additional wire and two butt connectors, as the two stock wires don't have a lot of extra length between them to reach each other. Nevertheless, I managed to do it with just the stock wires and one butt connector, so I'm sure you can too.

Once you have this done, to actually try it out, you have to do this:

• start the engine.
• set the emergency brake.
• have the transmission in Park.
• do not have your foot on the foot brake.
• flip the upfitter switch to the up (On) position.

Once all the conditions are met, the idle will go right up to about 1200. If you step on the foot brake, release the e-brake, or put the truck in gear, BCP (or SEIC) will disengage and the RPMs will drop back down to 600ish. If you undo/redo the correct conditions (i.e. take your foot back off the brake, etc.) the RPMs will go back up within a few seconds.