I waited for what seemed like forever for the DMV to send me the title to Old Smokey. It was so good to see the title written out correctly with my name and address, the Ford F-350 (shortened in DMV speak to F35), and No Leins Recorded, meaning only I have claim to the truck. Kind of nice to know I paid for the SuperDuty with cash, at least in my mind.
Tuesday April 21, 2026 — Old Smokey
Stationary Elevated Idle Control (SEIC) is a factory-programmed powertrain control strategy used in Ford SuperDuty Trucks to increase engine RPM while the vehicle is parked.
It is primarily used to drive auxiliary equipment via a Power Take-Off (PTO) system or to protect the battery and engine during extended idling.
See the official reference manuals below or visit the Ford Pro website for your specific year model. Details on the SEIC can be found on pages 78 – 81 of the 2026 Super Duty Body Builder Layout Book.
| Document | Upload Date | Downloads |
|---|---|---|
| 2026 PICKUP BOX REMOVAL BBLB | 4/10/2025 | Download (3.2 MB) |
| 2026 SNOWPLOW BBLB | 10/20/2025 | Download (435.5 KB) |
| 2026 GENERAL BBLB R1 | 1/6/2026 | Download (2.3 MB) |
| 2026 SUPER DUTY BBLB R2 | 2/16/2026 | Download (13.0 MB) |
To wire Stationary Elevated Idle Control (SEIC) on a 2026 Super Duty F-350 with a gas engine, you will need to bridge the “SEIC Request” wire to an Upfitter Switch while installing a resistor between the “Reference” and “Signal” wires.
On 2023–2026 models, the required wires are split between two locations:
The following colors are standard for the 7.3L or 6.8L gas powertrains:
| Function | Wire Color | Purpose |
|---|---|---|
| PTO Request | Yellow / Green | Triggers the high idle when it receives 12V power. |
| PTO Reference | Yellow / Orange | Provides 5V output for the resistor circuit. |
| PTO Signal | Green | Receives the resisted voltage to set the RPM. |
| Pass-Thru Wires | Varies (often Brown/White) | Use these to jump power from the engine bay to the cabin. |
To achieve a specific RPM, you must solder a resistor between the PTO Reference (Yellow/Orange) and PTO Signal (Green) wires in the passenger footwell.
Since your AUX switch wires are under the hood and your SEIC wires are inside the cab, you must use the Pass-Thru wires.
Ensure all safety “enablers” are met: Park, Parking Brake set, and feet off all pedals. Flip your Upfitter switch; the RPM should ramp up to your preset speed within 2–3 seconds.
For the 2023–2026 models, Ford’s logic follows a specific resistance-to-RPM curve. These values assume a standard 1/2-watt or 1-watt resistor.
| Target RPM | Resistance (Ohms) | Common Resistor to Use |
|---|---|---|
| 900 RPM | 35,200 Ω | 36k Ω |
| 1000 RPM | 21,900 Ω | 22k Ω |
| 1100 RPM | 15,400 Ω | 15k Ω |
| 1200 RPM (recommended) | 11,200 Ω | 10k or 11k Ω |
| 1300 RPM | 8,580 Ω | 8.2k Ω |
| 1400 RPM | 6,670 Ω | 6.8k Ω |
| 1500 RPM | 5,240 Ω | 5.1k Ω |
| 1600 RPM | 4,170 Ω | 3.9k Ω |
| 1700 RPM | 3,260 Ω | 3.3k Ω |
| 2000 RPM | 1,424 Ω | 1.5k Ω |
| 2400 RPM | 255 Ω | 270 Ω |
Everybody keeps telling me the 6′ 8″ bed on my SuperDuty is super-short. Maybe by SuperDuty standards where 8′ 2″ long beds are popular but it’s no 5′ 6″ bed found on some half tons and the 5′ bed on short bed Toyota Tacoma.
![Untitled [Expires April 27 2026]](https://andyarthur.org//data/photo_022262_large.jpg)
Here is a comparison of the short bed (6.75′) for the shortbed Ford F-350 and the standard bed (6.5′) for the 2011 Chevy Silverado standard bed:
| Specification | 2011 Chevy Silverado (Ext. Cab / 6.5′ Bed) | 2017–2026 Ford F-350 (SuperCab / 6.75′ Bed) |
|---|---|---|
| Wheelbase | 144.2 inches | 148.0 inches |
| Overall Length | 230.6 inches | 231.8 inches |
| Bed Length | ~78.8 inches | ~81.9 inches |
| Measurement | 2011 Chevy Silverado (Ext. Cab / 6.5′ Bed) | 2017–2026 Ford F-350 (SuperCab / 6.75′ Bed) |
|---|---|---|
| Bed Length (at floor) | 78.9 inches | 81.9 inches |
| Bed Width (at floor) | 62.4 inches | 66.9 inches |
| Width (between wheels) | 50.6 inches | 50.5 inches |
| Bed Depth (rail to floor) | 21.0 inches | 21.1 inches |
The A.R.E. MX Series is a “mid-rise” cap, meaning it features a sloped roof that starts at cab height and rises toward the rear. On both trucks, this design provides roughly 4 to 6 inches of additional height above the truck’s roof line. The total interior height (from bed floor to the cap’s ceiling) is significantly greater on the modern Ford F-350 because its cab and bed rails sit much higher off the floor than the 2011 Silverado.
| Measurement | 2011 Chevy Silverado (6.5′ Bed) | 2017–2026 Ford F-350 (6.75′ Bed) |
|---|---|---|
| Bed Depth (Rail to Floor) | 21.0 inches | 21.1 inches |
| Cap Height (Rail to Cap Top) | ~28.5 inches | ~28.5 inches |
| Total Interior Height (Floor to Cap) | ~49.5 inches | ~49.6 inches |
| Rise Above Truck Cab Roof | +4 to 6 inches | +4 to 6 inches |
For a 4×4 configuration, the Ford F-350 has a higher roof line relative to the bed floor than the 2011 Chevy Silverado. While the bed depth (floor-to-rail) is nearly identical for both trucks, the Ford’s cab sits taller above the bed rails.
The following table shows the vertical distance from the bed floor to the peak of the truck’s roof.
| Measurement | 2011 Chevy Silverado (Extended Cab) | 2017–2026 Ford F-350 (SuperCab) |
|---|---|---|
| Bed Depth (Floor to Rail) | 21.0 inches | 21.1 inches |
| Rail to Roof Peak | ~21.5 inches | ~23.0 inches |
| Total (Floor to Roof Line) | ~42.5 inches | ~44.1 inches |
Mom got this for me, and he's sitting behind the back seat, keeping an eye on everything going on from the back seat.
Saturday April 11, 2026 — Old Smokey
This pretty much the same configuration and components I have things on Big Red, but hopefully with lot less wire and colorful rat nests in conduit because I am mounting everything in the bed and not building it over 15 years as technology and knowledge evolves.
For simplicity's sake, I thought about powering the exciter wire on relay that connects between the starting batteries/alternator using a switched up-fitter switch, but I think I will just monitor the voltage on both the alternator/starting battery and solar using diodes (as electronic check valves) fed into the XY-60 voltage monitoring unit.
When either the solar or alternator is throwing out a mimimum of 14.1 volts, it will close the relay, and open the relay when the voltage drops below 13.1 volts (or whatever I set the XY-60 to). This way, when the truck is on, it will always charge the camp batteries, and when the truck is off but the solar is producing ample power, it will dump some of the extra power back to starting batteries during prolonged periods parked or at camp. With dual starting batteries on a gasser this less essential compared to the old rig, but batteries like to be trickled regardless when parked for an extended period. There is reason I could turn the key on Big Red and it started up with ease after being parked for 3 months.
I didn't include the various fuse blocks in this image, but everything will be properly fused. For the CB radio, I will just tap the upfitter harnasses off the starting battery on a switched upfitter switch. Also will include a shunt and amp meter for monitoring the input from the solar, as I'm always kind of interested in watching that.
In the future, I do want to add a second solar panel, and swap one of batteries out for lithium ion, but I will keep at least one lead acid for cold weather charging. But that needs to wait, as this project is starting to suffer from cost disease, though I am reusing 95% of electrical components and wire from the other truck.
By late summer, I want to add a cellphone booster and in late autumn add a line to use with a diesel heater for winter camping. I concede I won't have enough battery storage for the glow plug of the diesel heater, but the truck has remote start, so I can just double click the remote start button before starting the glow plug on the diesel heater.
Also in the out years, I may want to add a portable refrigerator. They do use quite a bit of current, but especially if I add a lithium ion battery, this could fit into the set up without lot of additional change.
Sunday April 12, 2026 — Old Smokey
Most people think of remote start as a luxury reserved for those sub-zero January mornings or the sweltering heat of July. When I first got my Ford SuperDuty—affectionately known as Old Smokey—I figured the remote start on my key fob would be a “sometimes” tool, something I’d pull out for camping trips or during a cold snap. But lately, I’ve noticed a shift in my routine. Whether it’s a mild spring afternoon or a quick stop at the hardware store, I find myself hitting that button twice before I even reach the door handle.
It might seem like a small thing, but the more I do it, the more it makes sense. My ritual is simple: as I’m walking back to the truck, I click the remote start. By the time I’ve covered those last few yards, I hit the unlock button, climb in, and slide the key into the ignition. It’s almost no extra effort compared to starting it manually, but those few seconds—or a minute or two if I’m taking my time—make a world of difference for a heavy-duty machine like this.
The primary reason is purely mechanical. A SuperDuty isn’t a compact car; it’s a powerhouse. By starting Old Smokey before I’ve even touched the door, I’m giving the engine a head start on getting the oil flowing through the system. It gives the alternator a chance to start spinning and the grease a moment to loosen up before I ask the truck to shift into gear and move its own weight.
There’s also the electrical side of things to consider. When you unlock the doors, the dome lights kick on, the onboard computers wake up, and various sensors start drawing power. If I start the truck first, the alternator is already providing that juice. I’m not loading down the starting batteries with all those peripheral electronics before the engine has even turned over. Plus, getting the heater or the AC moving just a minute early adds a layer of comfort that’s hard to give up once you’re used to it.
I know there are critics out there. Some folks argue that remote starting is a waste of fuel or that “excessive idling” wears out an engine prematurely. While I wouldn’t leave Old Smokey running in the driveway for twenty minutes for no reason, I have my doubts that a commercial-grade engine is going to suffer from a sixty-second warm-up. In the grand scheme of things, I might burn an extra gallon or two of fuel per year. To me, that’s a tiny price to pay for reducing the wear and tear on my battery and engine components.
At the end of the day, it’s about longevity. Even if the engine is still warm from a previous trip, that extra minute of circulation ensures everything is fully stabilized before I pull out of the parking spot. It’s become as natural to me as using power door locks. It might seem silly to some, but for me and Old Smokey, it’s just the right way to start the journey.
