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Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems

Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems

Item # SM99945
Our Price: $269.00
You Save: $46.00
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Monitor your supplemental braking system from the cab of your RV as you're flat towing. Transmitter installs in your towed car and sends signals to the plug-in monitor in the RV to let you know the system is working properly. 1-800-940-8924 to order Demco accessories and parts part number SM99945 or order online at Free expert support on all Demco products. Great prices and Fastest Shipping for Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems. Accessories and Parts reviews from real customers.
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  • Reviews (61)
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  • Videos (6)
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Demco Accessories and Parts - SM99945

  • Tow Bar Braking Systems
  • Brake Monitoring
  • Transmitters
  • Demco

Monitor your supplemental braking system from the cab of your RV as you're flat towing. Transmitter installs in your towed car and sends signals to the plug-in monitor in the RV to let you know the system is working properly.


  • Lets you know your towed vehicle is braking properly
    • LEDs light up on the monitor when the brakes are applied
    • Audible alert sounds off if the brakes stay on too long
  • Transmits signal wirelessly from towed car to motorhome
    • Transmitter splices into the towed vehicle's wiring
    • Receiver plugs into the RV's 12-volt accessory outlet and mounts on the dashboard
  • Made in the USA
  • 1-Year limited warranty

Demco Wireless Coachlink Braking Monitor

9599005 Demco (Formerly SMI) Wireless Coach Link Braking Indicator System for Supplemental Braking Systems

Replaces Demco SBS SM99945

Installation Details SM99945 Installation instructions

Video of Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems

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

Video Transcript for Demco SBS Wireless Coachlink Review

Demco's coach link will take your breaking system to the next level. By giving you a wireless receiver inside of your motor home that's gonna give you real time feedback of when the brake pedal is being applied from your breaking system and with the traditional Demco style breaking systems you do get a monitor light included that will go on the back side of your mirror on the dash. So that way you can see it in your rear view camera, but depending on your motor home you might not have a camera at the top or where your camera's pointed for backing up. It just may not be suitable for where the monitor lights located. And maybe the monitor that you have just isn't the clearest monitor. So you may still be aimed right at it, just really can't tell that it's coming on.

So getting a wireless version will allow you to have something right there in the dash to provide you that feedback that's much more easy to see and you also get audible feedback from it as well. Once you install your transmitter in your vehicle your receiver is here inside your motor home. It's simply powered by an auxiliary cable. So your typical auxiliary outlet. Now a lot of the modern motor homes these days are starting to do away with this type of connector, and just going with the USB style.

USB is only a five volt output and it's of course it's a different connector shape. So this won't plug into it, but this requires 12 volts. So if you don't have one of these in your motor home we do offer 12 volt kits available here at etrailer. So that way you can install an outlet similar to this and be able to have the power you need for your coach link system. So we're now hooked up to our motor home.

I'm gonna go ahead and press the brake. And when I hit the brake you can see there that it is now illuminated showing us that the brakes have been applied. I'm gonna continue to hold the brake and there's our audible feedback. And this is important. I'm gonna go ahead and let off the brake.

And when I let off the brake you see there that it went off, but what's important about that audible feedback is that if you're just driving down the road like normal, you press your brake. You let off, you're not really paying that much attention and you hear that beep. Well you know then, "Hey, my brakes are probably still applied. Something's going on in my system. I need to pull over and take care of it." So I do really like that audible feedback. There are situations where I feel that it's gonna be kind of annoying if you're stuck in traffic, maybe in a crowded city area or something like that. We can go ahead and turn that buzzer off. So that way it's not beeping at us. When we're sitting at a stop light, stop sign, or just in heavy traffic and stuff where you know you're the one that's causing the brakes to still be applied. The buzzer is mainly there for when you're cruising down the highway, you hit the brakes cause you're slowing down from the guy in front of you. And then if you hear that noise after you've let off you know there's an issue. So it's really nice you get that feedback. But even without the buzzer, we can see every time we press and release, we get our signal there letting us know that our systems working properly. So it's really useful for those long trips where you're just concerned, "Hey am I gonna be able to make it there without being an issue" Well, this way you can verify the entire trip that you're getting there okay. So here we have our transmitter, the transmitter's just a two wire component and all it needs is it typically will hook into like a stoplight switch on your vehicle. 'cause all it needs really is just the power signal going to it to let it know that the brakes are being applied. So as long as your vehicle has a traditional stoplight switch that is an on off 12 volt signal. This will hook right into the vehicle's factory stoplight switch. If your vehicle has a pedal position sensor that uses a five volt reference you will need a different way to activate this. But we do have custom fit switches from Roadmaster here that will install in your vehicle to give you a 12 volt on and off stop light switch. And then depending on your breaking system like the air force one that we installed here there's a read switch located on the cylinder that will provide us with that stop light switch. And that's what we actually tapped this into today. It works directly with the air force one but it can be installed on pretty much any breaking system. And that completes our look at Demco's wireless coach link..

Customer Satisfaction Score:

Customer Reviews

Demco Wireless Coachlink Braking Monitor for Flat Tow Brake Systems - SM99945

Average Customer Rating:  4.8 out of 5 stars   (61 Customer Reviews)

Monitor your supplemental braking system from the cab of your RV as you're flat towing. Transmitter installs in your towed car and sends signals to the plug-in monitor in the RV to let you know the system is working properly.


Excellent addition to the Demco braking system! Should be a standard component.
It allows verification of towed vehicle braking from the coach without distraction from forward vision.
Very pleased with ease of installation and use.
Thanks etrailer for another quality product!


The Demco Wireless Coach link arrived quickly like always from etrailer.
Everything in the etrailer pictures are exactly what you will receive. Hooking it up and setting it up could not be easier. I installed it in a 2014 Ford Edge. Only two wires to hook up. White goes to ground and the red wire was sliced into the cold side of the brake pedal switch. It was a purple and white wire. Found it by tapping on the brake pedal with a meter on each wire. Tuck everything away in the Edge and tested the unit. It worked perfectly as expected. I did not actually test it behind the motorhome as it was not available. If I run into any issue being about 50' away, I will update the review. So far, it's great!


Excellent product offering the ability to easily monitor the tow vehicle brake activation on a monitor right in front of you is a welcome change. Many thanks to Jim D for his idea of cutting off the LED brake indicator plug and butt connecting it to the transmitter. I took Jim's idea one step further and went to my local electronics store and purchased the same kind of plug and wired it to the SMI Transmitter. This way I can still use the LED indicator as a backup if ever needed by simply unplugging the transmitter and plugging it back into the LED. With the new plug I purchased the SMI Red Wire was connected to my new plug's Brown wire and the SMI White wire was connected to my new plugs Red wire as shown in the attached picture. Plugged it up and it worked great. So much simpler than having to splice into the SMI Duo wiring harness.

Chuck R.


Thanks for the note. In answer to your question, Yes I still like the SMI dash monitor and it is still working great. Makes it a lot safer seeing right in front of you if your brakes are activated. Thanks


I order a lot of things online and I don’t think there’s better communication out there than with Etrailer on your deliveries. The E trailer team goes above and beyond to make sure you’re notified end helping out with any issues you have on your order I enjoy working with that company.


Just installed the SMI CoachLink 900 Wireless Transmitter and Receiver Braking Indicator Set in my Honda Fit and Navion Motorhome. Less than 10 minute install to my existing Stay and Play Duo brake system. It just can't get any easier to have a better indication of how my braking system is performing for me from the drivers seat in the motorhome. I added an indicator light in my Honda to let me know that the Duo brake system is active when I turn on my GForce Controller.


Took a minute to figure out the wiring , but once that was set easy to install.


I swapped my demo stay in play out of my 89 bronco 2, into my 2016 jeep jk. The ignition key position in the bronco had to be in accessory to unlock the steering wheel, this allowed me to use the vehicle brake switch to activate the demo coachlink transmitter. On my jeep the key is off when towing so I needed a separate brake switch to activate coachlink. I purchased the roadmaster universal brake switch. I really like this switch. It has an electronic position switch that attaches to the brake pedal arm to provide an accurate indication of brake position in the motor home while driving.


Easy to install with the separate brake switch and works great.


I installed a demco air force 1 on my nautilus and purchase this monitor to replace the dumb lights that stick to the mirror of the toad. The wiring diagram for the coachlink was inconsistent with the wiring on the demco. Stupidly rather than call demco i followed the coachlink wiring. The result was it did not work. Called coachlink. They Pete great and aware of the issue. They replaced the sensor on the actuator no charge. Turns out that the coachlink also fried. I am onnthe road so i ordered a replacement which etrailer got to us. The service eas great just annoyed i had to pay another xxx$ for the second unit


Just what I needed



Still working as intended, very happy with this product


It arrived prior to my deadline as promised. There were no instructions in the Coachlink box but I found them on the web easily enough. I have made three purchases from etrailer and have leaned on them with questions and for technical support. Messages are returned very quickly and they always are helpful. Prices are competitive. I try to order from etrailer whenever possible as they are very easy to work with and are always available with help if needed. Great company and people.

Steve F.


Its been a year since my review and I havent needed any parts from eerailer. My opinion has not changed, they are they are one of the top places I go to for prices and help.


Great product! I finally broke down and installed this Demco product after numerous efforts to get reliable feedback on braking status from the Air Force One in my toad ... seeing LEDs from the motorhome rear camera and running wires through the wiring connect to a dash light were all sub-optimum. Installing the Demco system was easy, the instructions include wiring diagrams for a number of different braking systems. Once the toad wiring was complete I located the control box where I could see it while driving, plugged it in ... and it worked perfectly! Great peace of mind, I use it as part of my pre-departure check list and glance down to get a confirmation most times I use the brakes.


Easy installation. Simply replaced the LED brake indicator previously installed on the back of rearview mirror with the wireless transmitter supplied with this kit. Transmitter was mounted (using hook and loop tape), directly underneath the SMI G-Force Controller, which is mounted on the tow-kick panel and B-Pillar (besides the driver's seat). Although it appears this location might be in the way of the hood release, it isn't. There is still plenty of room for the hood release to operate on the 2014 Honda CR-V....other models may not have room, but the 2014 Honda CR-V has room. The end is cut off the LED brake indicator and butt-connected to the end of the transmitter and plugged in. The wires were removed from the tie that secured them to the dash (just behind the steering wheel adjustment lock lever) and excess wire was tucked under the carpet, easily accessible if transmitter should need moving later. Receiver activated as expected.


We purchased the Stay N Play brake system with the wireless transmitter, and wish we had done it years ago, instead of messing with the Brake Buddy that we had before. It is so easy now to get our Explorer ready to tow behind our RV, and we like the 'instant' breaking that the Stay N Play affords instead of dealing with the 'lag' that we had in our Brake Buddy. We would definitely recommend this excellent product.


Awesome tool for peace of mind that the braking system is working properly when towing. It was very difficult to see the provided light through the rear view camera and now I know immediately when the towed vehicle brakes are applied. Easy installation I did it myself.


This wireless brake lighting monitor works perfectly with my SMI Duo brake assist system. No constantly looking at rear camera on my motorhome. etrailer videos so helpful with entire series of installs on my Wrangler for flat towing.... Tow lights, brake relay, towed vehicle battery charger, SMI Duo system, and this monitor.


I am very happy with the CoachLink 900. Easy to hook up and use.



Its been working just fine. Still happy with it.


Very satisfied with this product it was easy to in stall and give you a good loud alarm . I had the old SMI silent partner system and it came with an alarm so I missed it until I bought this one . Again work great and easy to install.


After towing over 7,000 miles, this works great with no problems. Easy install. I can confirm the brake on tow vehicle is working properly each time I apply brake in MH. Highly recommend for anyone towing a vehicle with active brakes.


Excellent product. I use the Ready Brute mechanical brake system hitch. I tow a 2017 Wrangler. This simple to install Coach Link works every time. I’ve used mine for a year now. Just plug it in and boom it works.


The LED indicator for the back of the rear view mirror in the tow car is not always visible, sunlight, glare,etc. This unit makes monitoring the brake system easily visible.

by: did a great job getting my order processed and shipped. Although I'm not a big fan of UPS SurePost, everything worked out great this time. The SMI Coachlink wireless device seems to work as advertised. The install was very straight forward. I've been dealing with SMI for several years now. They have always been first rate. No I think if first rate also. Thanks again for the great service.



Received product without instructions and package had been opened.
Printed instructions off of web page to install.
Product works great but very hard to see LED in writing of on control box, suggest you place LEDs out side of the writing and increase the brightness.
My wife has to check the lights because I cannot see them during the daylight hours.


The wireless break indicator unit works well although it is difficult to see the power on light. Installation was a little “dicey” given the small gauge of the wiring but it went pretty smoothly.


As usual, ordering process was simple and efficient. Item was shipped almost immediately and received as promised. I have installed the Wireless Coachlink which was simple with the included instructions and it works flawlessly. I will continue to do business with based on their competitive pricing and superior customer service.

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Employee Lindsey S
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Employee Jeff D
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Employee David F
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