One-Person Electrical & Air Brake Trailer Diagnostics
Verify trailer lighting, air supply, and brake activation quickly and accurately, without a second person in the cab, without moving the trailer, without software.
Trailer Dr. is a portable air brake and electrical trailer diagnostic tool built for technicians who need fast, reliable testing in shops, yards, and mobile roadside environments. The smallest and most powerful tool in its class, Trailer Dr. delivers 30 amps of output in a 15.2 lb waterproof unit used by fleets, repair shops, and mobile service operators across the United States.
How It Works
One Person. One Tool. Complete Testing.
- 01
Connect to the trailer
Plug into the trailer's 7-way connector. One person can run the full test from the rear of the trailer, with the remote.
- 02
Test lights, air, and brakes
Activate electrical functions, supply air, and trigger brakes, all from where the problem actually is.
- 03
Confirm and clear
Verify repairs on the spot before the trailer returns to service. Test once, confidently.
One-Person Operation
Activate lights, air supply, and brakes from the rear of the trailer. No cab access, no second technician required.
Waterproof & Rugged
NEMA-rated polycarbonate enclosure built for cold, wet, dusty, and harsh field environments, from the shop floor to roadside.
Most Power in Its Class
30A output at 12.8 VDC, delivering 2/3rds more power than leading competitors in the most compact package available.
Smallest & Lightest
At just 15.2 lbs, Trailer Dr. is the most compact unit in its class. Carry it between trailers in any shop or yard. No permanent mounting required.
of commercial vehicles failed 2025 DOT-standard roadside inspections.
Why It Matters
Catch Problems Before They Ground Your Fleet
Brake systems are the #1 cause of out-of-service failures (41%), and lighting defects are #3 (14%). Trailer Dr. is built to test both, so your crew can catch and confirm repairs before the trailer ever faces an inspection.
See How It HelpsTrusted by Professionals
What Our Customers Say
“We run 12,200 trailers a year using his product. We are very happy with his product and customer service.”
“Excellent quality trailer light and ABS tester. Rugged unit can handle just about anything and perform. An essential for any shop.”
“This product allows for very efficient diagnosing of air brake issues and electrical problems. Saves our employees time and frustration. It's the only one-man diagnostic trailer tool I'd recommend.”
“Great purchase!! User friendly and saves time. Best purchase for trailer maintenance available.”
“Great product, great for one man repairs and test on trailers. Remote controlled from under the trailer, back of trailer, or on top. Great for wiring failures.”
Ready to Keep Your Equipment Moving?
Schedule a demo and see why Trailer Dr. is the most compact, most powerful trailer diagnostic tool in its class.