RV Technicians and Other Professionals!

Build your own EXCLUSIVE Magi-Box trailer wiring tester ...
from simple, readily available parts.

These plans are not available anywhere else on the Internet.
This compact tester requires no battery or external power source
and will fit in your toolbox or mobile service cart.



The Magi Box

Complete Plans and
Assembly Instructions

Now only $9.95
  • Test the trailer plugs on both the tow vehicle and the trailer with one portable unit. Take it anywhere!

  • Complete do-it-yourself plans, step by step wiring diagrams and assembly instructions.

  • No electronics knowledge required - simply follow the step-by-step color coded wiring guide. Each circuit is high-lighted on a separate page. Just complete one step then go to the next!

  • Uses "off the shelf" components all protected by on-board circuit breakers.

  • Tests for proper battery polarity ...

  • Tests signal lights, running lights, backup lights and brake circuit outputs.

  • Allows you to work on the separate circuits and activate each one of them with the flip of a switch.

  • Tests brake controller output ... allows easy brake controller adjustment.

  • Test 4 pole, six pole, standard RV 7 pole and ASME 7 pole wiring codes.
    Just wire up the appropriate adapter.
Similar testers cost $600+
Build your own and save!

Order Your Plans Today!
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