Pocket Tester — for 7 Way Round Pin Trailer Electrical Systems
The Pocket Tester is a fully self-powered, portable 7-way trailer diagnostic tool designed for mechanics, mobile techs, and fleet service teams who need accurate lighting checks without the bulk of a shop cart or the need for a connected tractor.
It plugs directly into the trailer’s 7-way, powers the lighting circuits from its internal battery, and provides clear LED feedback for opens, shorts, and crossed wiring conditions. With its wireless remote and magnetic storage, a complete lighting check can be performed by one person — even from the back of the trailer.
The device is built to handle daily use in shop, yard, and roadside environments, offering a simple and reliable way to test lighting circuits wherever the trailer is parked.
What It Does
- Powers and tests trailer lighting circuits without a tractor
- Detects opens, shorts, and crossed wiring on 12V trailer systems
- Includes short-circuit protection to safeguard internal components and trailer wiring
- Allows you to view ABS blink codes with a single press (for trailers equipped with blink-code ABS modules)
- Activates lighting circuits remotely using the included wireless remote
- Operates entirely on internal power for portable diagnostics anywhere
Why It Matters
Traditional test carts are bulky, rely on long cables, and must be wheeled into position. The Pocket Tester eliminates all of that. You can walk directly to any trailer — in the yard, shop, or roadside — plug in, and start checking circuits immediately.
- No lining up a tractor.
- No dragging heavy equipment across the shop.
- No second person needed.
- Just fast, practical lighting diagnostics wherever the trailer sits.
For troubleshooting guides, visit our Support Page.
For warranty details, see our Warranty Page.
FAQ
Does the Pocket Tester work without a tractor?
Yes. It’s a fully self-powered unit with an internal rechargeable battery, allowing you to test trailer lighting and circuits anywhere without connecting to a truck.
Can the Pocket Tester be used without the remote?
Yes. The device has a local auto-cycle mode that runs lighting tests using a single button on the base unit. Instructions are included in the manual and on the support page.
Can it test ABS systems?
Yes. A one-button ABS test sends the correct signal to the trailer’s ABS module, causing the ABS light to display any stored fault codes if present.
Is the remote included?
Yes. Every Pocket Tester includes a wireless remote for true one-person testing from the back of the trailer.
What is the remote range?
The remote can reach up to roughly 150 feet in open, unobstructed conditions. Range may decrease behind loaded trailers or in areas with materials that block RF signals.
What if I lose the remote?
A replacement remote can be purchased separately and easily paired with the base unit. Instructions are included in the manual and on the support page.
Is the remote water resistant?
No. The remote is not water resistant and should be kept away from rain, moisture, and water sources.
How long does the battery last?
Battery life varies. With normal inspections—cycling through circuits—you can expect days to weeks of runtime. Duration will be shorter if circuits are left on continuously or if the trailer uses incandescent lamps.
How do I charge the device?
The Pocket Tester charges using the included 2.1mm DC jack power supply. Only the provided charger should be used to protect the internal battery.
How long does charging take?
A full charge takes about three hours. Fast charging is intentionally not used to extend the long-term lifespan of the internal battery.
What happens if the battery becomes low?
If the battery cannot supply enough current, the indicators will flash red to signal low voltage. Lights may dim or shut off until the device is recharged.
What safety features protect the trailer wiring?
The Pocket Tester automatically cuts current when a short is detected to prevent arcs, heat, or potential damage. A brief cooldown occurs before re-energizing the circuit to protect components.
Can I leave the unit plugged into a trailer?
Yes, the unit can remain connected. Just be aware the internal battery will continue to drain depending on which circuits are active.
Is this tester compatible with 24V trailers?
No. The Pocket Tester is designed exclusively for 12V trailer systems.
Does it work on older trailers with incandescent lights?
Yes. It supports incandescent-equipped trailers, but expect more frequent charging with heavy use since these lights draw more current.
How durable is the Pocket Tester?
The housing is made from an impact-resistant ABS alloy designed for daily shop and yard use. It is not enclosed in a TPU shell, so reasonable care is recommended.
Can it operate in extreme temperatures?
The unit includes a built-in temperature sensor. To prevent battery damage, it will not charge or operate in extremely hot or cold conditions.
Is the 7-way plug replaceable?
Yes. The 7-way connector can be replaced if damaged. Replacement plugs are available—contact support for pricing and service details.
Being a trailer mechanic for over 30 years this by far has being the best trailer light tester I have ever owned Small enough to fit in my tool box drawer. This tester is so good other mechanics are always asking me to borrow it cause they dont want to use the big light tester the shop provides.
This tester has been a huge help for me on checking/diagnosing multiple trailers at a time and or during service calls in a fast manner, love the extra ABS feature ,also not big and bulky,Saves me time and headaches by finding electical issues quicker/been a mobile tech for 9 years and this has certainly changed the game for me on diagnosing electrical issues on trailers.