Already Have a Dash Cam? How to Add a Rear Camera for Temporary Towing

You already have a dash cam in your car, but occasionally tow a box trailer, caravan or borrowed trailer. Once it is coupled, your existing rear camera may show the front of the trailer rather than the area behind it. You do not necessarily need to replace the dash cam: you need a separate view from the back of the trailer.

Quick answer: the MCNE TA138 (F25C) can provide an independent, phone-viewed rear camera for temporary towing. Keep your existing dash cam for its normal recording duties. Do not assume the TA138 connects to its rear-camera socket, displays on its screen or adds footage to its recordings.

Why the existing rear camera is not enough

A camera mounted on the towing vehicle cannot see through an enclosed trailer. Even with an open trailer, cargo can block its view. Moving the viewpoint to the rear of the trailer addresses a different visibility problem from recording the road behind the car when travelling without a trailer.

Extending an existing dash cam’s rear-camera cable is not automatically a solution. Camera inputs, power, connectors and video formats are model-specific. Only use an extension or additional camera explicitly approved for the original system.

How the TA138 works alongside your dash cam

The MCNE TA138 solar magnetic WiFi camera, listed as F25C, uses its compatible smartphone app for live viewing. The product lists a 9600mAh rechargeable battery, solar charging, USB-C charging, an adjustable magnetic mount, infrared night vision and an IP68-rated housing.

The arrangement is straightforward: the original dash cam continues its normal operation, while the trailer camera sends a separate local WiFi view to a compatible phone. No separate camera monitor is required. This is an additional viewing system, not a universal wireless rear-camera upgrade for any dash cam.

Check three things before buying

1. Is there a suitable mounting surface?

A magnetic mount needs an appropriate magnetic surface. Aluminium, fibreglass and many caravan panels will not hold it. Check the actual trailer, not just its appearance. A thin, curved, dirty or damaged panel may also be unsuitable for secure mounting.

Follow the mounting instructions and check retention before travel. A magnet does not mean the camera can be attached anywhere or is guaranteed to remain secure under every road condition. If there is no suitable surface, ask about an approved alternative rather than improvising a mount.

2. Will the phone connection work in your setup?

Confirm the correct app and phone compatibility before the trip. Test the camera at the intended rear position with the trailer attached and the phone in its intended location. Metal bodywork, cargo, distance and obstructions can affect the connection; do not choose it on an assumed universal range.

3. Can you use the display appropriately?

A phone-based view needs planning. Set it up while safely parked and follow the phone and screen rules for your state or territory and licence class. A phone holder does not automatically make every use lawful. For example, NSW guidance on phones and driver-aid screens sets specific restrictions. Do not hold or adjust the phone while manoeuvring.

A practical setup before your first trip

1. Charge first. Use USB-C charging according to the manual and check the battery level before relying on the camera.
2. Choose the viewpoint. Temporarily position it at the trailer rear, clear of doors, loads, lights and the number plate.
3. Connect while parked. Follow the supplied instructions for the exact app, network and password; these are not interchangeable with your dash cam’s app.
4. Adjust the image. Check the useful area behind the trailer, camera orientation and nearby reference points. A wide view can make objects look smaller.
5. Test the complete combination. With the vehicle secured, use stationary objects to check coverage. Verify that the image updates rather than displaying a frozen frame. Recheck mounting and connection after a short, safe test journey.

Solar charging helps, but is not unlimited power

The solar panel supplements the rechargeable battery. Sunlight, shade, panel orientation and viewing time affect how much energy is available. Do not assume solar charging will keep up with continuous use or that the quoted battery capacity guarantees a particular runtime.

Charge before departure, keep the panel clean as instructed and check the battery during use. After the trip, remove and store the camera as directed, particularly if the trailer will be left unused.

Will it record into my existing dash cam?

Do not assume so. The TA138 product page lists app-based live viewing, playback and settings, but this does not establish integration with another recorder or a complete continuous-recording workflow. Confirm storage requirements, recording behaviour and export options if saving evidence is essential.

Likewise, WiFi does not mean 4G, remote cloud viewing or a feed available from anywhere. If your phone normally connects to your dash cam over WiFi, you may need to switch networks to view the TA138. Test any interaction with wireless CarPlay or Android Auto before relying on both together.

When a dedicated monitor system makes more sense

For frequent towing, multiple views or a display that does not occupy your phone, compare a matched camera-and-monitor kit. This is especially relevant when the magnetic surface or local phone connection is unsuitable. Our wired versus wireless truck camera guide explains the installation trade-offs.

For occasional towing, the TA138 offers a way to add a separate trailer viewpoint without replacing a working dash cam. It remains a visibility aid: use mirrors, direct checks and a spotter where appropriate. Stop if the view or connection becomes unreliable.

View the MCNE TA138 camera, compare MCNE Truck Camera Systems, or ask MCNE about your trailer setup.