Electronic Specialties’ 220 Trailer Buddy 4/5 PIN – Audible Trailer Wiring Tester


With the Trailer Buddy, one person can check a vehicle’s trailer wiring harness in approximately 30 seconds. The tester will verify correct and incorrect electrical functioning of the vehicle’s 4- or 5-pin flat trailer harness.

Unique to the Trailer Buddy, the tester emits an audible signal, assigning a specific beep for each lighting function. To test, the user activates each light (brakes, running, right turn, left turn, reverse) and listens for the beep. This patent-pending system saves time, helps avoid the need to walk back and forth for verification and does not require a second person.


This idea came from the frequent need to check trailer wiring. Trailer lighting failures are very common, and unique time-saving tools are always needed to track down the cause. For example, when a trailer light doesn’t work, people automatically assume the problem is in the trailer. However, many times the problem is in the tow vehicle.

For technicians, Trailer Buddy offers a quick way to verify tow-vehicle wiring and new harness installations. Once a vehicle has been newly wired, a quick test is needed to check one’s work.


This product is designed to save technicians time. Techs can perform a complete trailer wiring test in about 30 seconds. No second person is required, and no walking back and forth to verify.
• Each signal from vehicle emits a unique tone.
• Loud beep can be heard over shop noise.
• Just apply brakes, turn signals, running lights& engage reverse.
• Tester also emits unique tone for any shorts in the wiring.
• Tests left and right turn signals, brakes, running lights, reverse and wiring shorts.


Steve White
Electronic Specialties
Email: electro_spec@msn.com
Website: www.esitest.com

Suggested retail price: $27.95