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Towed Car Conversion Kit - Demco SBS Air Force One to Stay-IN-Play DUO Supplemental Braking System

Towed Car Conversion Kit - Demco SBS Air Force One to Stay-IN-Play DUO Supplemental Braking System

Item # SM99231
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Our Price: $998.30
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Demco Accessories and Parts - SM99231
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Kit lets you convert your Demco SBS Air Force One for use with the Stay-IN-Play DUO supplemental braking system. Call 800-298-1624 to order Demco accessories and parts part number SM99231 or order online at etrailer.com. Free expert support on all Demco products. Guaranteed Lowest Price and Fastest Shipping for Towed Car Conversion Kit - Demco SBS Air Force One to Stay-IN-Play DUO Supplemental Braking System. Accessories and Parts reviews from real customers.
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  • Reviews (3)
  • Q & A (3)
  • Videos (2)
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  • Why etrailer?

Demco Accessories and Parts - SM99231

  • Tow Bar Braking Systems
  • Conversion Kit
  • Demco

Kit lets you convert your Demco SBS Air Force One for use with the Stay-IN-Play DUO supplemental braking system.


  • Convert the set up in your towed car from the Demco SBS Air Force One (SM99243) to be able to use the Demco SBS Stay-IN-Play DUO (SM99251) supplemental braking system
  • Includes all of the hardware and components needed to complete the conversion

6218 Demco SBS - (Formerly SMI) Towed Car Conversion Kit from Demco SBS Air Force One to Stay N Play Duo Supplemental Braking System

Replaces Demco SBS SM99231

Video of Towed Car Conversion Kit - Demco SBS Air Force One to Stay-IN-Play DUO Supplemental Braking System

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of SMI Tow Bar Braking Systems - SM99231

Michael: Hi there, I'm Michael with etrailer.com. Today we're taking a look at the Demco towed car conversion kit for SMI Air Force One to Stay-IN-Play Duo Supplemental Braking System. Your Air Force One is going to work with your RV's that have air brakes. It's going to take the air pressure from the RV and send it to the actuator on your vehicle, to apply the brakes there. Your SMI Stay-IN-Play is going to work off the brake signal, coming from the RV and apply the brakes in your towed vehicle. This kit is going to allow you to convert from the Air Force One to the Stay-IN-Play.Now I'm going to go out on the limb here and assume that if you're looking at this kit, maybe you had an RV before that had air brakes.

So you got the Air Force One. Now you got a new RV that doesn't have air brakes, so you're wanting to convert. The good people at Demco have created this kit for your situation, so that you don't have to buy the whole Stay-IN-Play Duo kit and have redundant parts. Any of the parts that you already have for the Air Force, one that will work with the Stay-IN-Play are not included in this kit. So you're really only buying the things that you need.

Now with that said, you are going to get a lot of different installation things like your zip ties or wire loom to clean it up. They also include these Quick Splice Connectors. Now we've done a lot of installation of the Demco products. And one thing that we have found is, these Quick Splice Connectors, no matter what kind of installation you're doing, these are not your best option, they come loose, they just don't hold up.So we always like to recommend that, you get a Butt Connectors, and if it's going to be outside the vehicle or outside the cab of the vehicle, specifically, we recommend Heat Shrink Butt Connectors. You can find those here at etrailer using part number DW 05744-10.

Those are just going to help keep your connections much more secure.You are going to have to splice into your wiring kit, whether that's a diode wiring or bulb and socket wiring, to get your wires connected to the brake signal coming from your RV. And you want to make sure that those connections are secure. Like I said, this kit going to include everything you need and nothing that you don't, so that you can convert your SMI Air Force One to a Stay-IN-Play Duo. That's going to complete our look at the towed car conversion kit for, from SMI Air Force one to Stay-IN-Play Duo Supplemental Braking Systems..

Customer Reviews

Towed Car Conversion Kit - Demco SBS Air Force One to Stay-IN-Play DUO Supplemental Braking System - SM99231

Average Customer Rating:  4.3 out of 5 stars   (3 Customer Reviews)

Kit lets you convert your Demco SBS Air Force One for use with the Stay-IN-Play DUO supplemental braking system.

- SM99231

This is a conversion from a Demco Air Force One to a DUO braking system. The parts were all provided and in good order. My disappointment with Demco was the installation instruction booklet provided. The installation booklet was for a complete DUO installation, not the conversion kit that I ordered. It was challenging to sift through the instructions and determine which components were needed and which were already installed from the previous Air Force One system. Wiring was particularly hard to figure out. A call to Demco was required, but to their credit, they resolved my issue, but if the instructions provided were truly for the conversion kit only and not the complete installation package, I don't think any call would have been necessary and installation time would have been reduced.

- SM99231

- SM99231


Ask the Experts about this Demco Accessories and Parts

  • Second Vehicle Demco Air Force One Kit for 2021 Chevy Traverse Flat Towed
    When installing the Demco Air Force One on a new vehicle we actually have the second vehicle kit part # SM99209 which comes with everything needed for just the new vehicle. You most likely could take the tow bar lighting kit from the old vehicle and install on the new Traverse but otherwise you could go with # RM-152-1676-7 for a new diode setup with everything needed. This would work great with the Blue Ox base plate you are planning on getting part # BX1734 and Blue Ox tow bar like...
    view full answer...
  • Installation Details for SMI Air Force One to Stay-in-Play DUO Conversion Kit
    I spoke with my contact at SMI regarding the Air Force One to Stay-in-Play DUO Conversion Kit # SM99231 referenced in your question. He stated that they do not have a specific installation guide for the conversion kit but that you will simply follow the guide for the standard SMI Stay-IN-Play DUO Braking System # SM99251 during installation. I have attached the Stay-IN-Play DUO installation details so that you can look through them.
    view full answer...
  • How Do you Know When Demco SBS DUO Is Applying Motorhome Brakes
    The Demco SBS DUO part # SM99251 which is what the # SM99231 fits has a monitor display light that you will be able to see light up when the brakes of the towed vehicle are being applied. If you wanted to have a person sit in the towed vehicle the first time just to be sure you certainly could but if you are seeing the light this is pressing the vehicle brakes.
    view full answer...

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Info for this part was:

Employee Jameson C
Expert Research:
Jameson C
Employee Jacob T
Video Edited:
Jacob T
Employee Wilson B
Written by:
Wilson B
Employee Jonathan Y
Video by:
Jonathan Y
Employee Conner L
Installed by:
Conner L
Employee Michael B
Installed by:
Michael B
Employee Kristina F
Updated by:
Kristina F

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