Free Ground Shipping on Most Orders Over $99.99 In USA



ESI #220 TRAILER BUDDY 4/5 Pin - One Man Trailer Wiring Tester

Electronic Specialties Inc

Sale price $33.75 Regular price $55.68

Shipping calculated at checkout.

ESI #220 TRAILER BUDDY 4/5 Pin - One Man 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.
Features and Benefits

  • Each signal from vehicles emits a unique tone
  • Loud beep can be heard over shop noise
  • Apply brakes, turn signals, running lights, engage reverse and listen
  • Greatly reduces time spent verifying vehicles trailer wiring
  • Tester also emits unique tone for any shorts in the wiring.
  • Very simple and easy to use, saves time

Product Specifications

Lighting Circuits Tested:

  • Left Turn Signal
  • Right Turn Signal
  • Brake
  • Running Lights
  • Reverse
  • Wiring Shorts

WARNING: California’s Proposition 65