How to Test 7 Way Trailer Wiring Without a Tester

If you are having trouble with your electrical and are not sure if it is your dump trailer or truck, here is a quick trick to test your trailer without buying a tester.


This also works for non dump trailers.


Grab any conductive two pronged tool and insert it into the top two terminals on your 7 way plug that are your 12 volt and running light terminals. If your lights turn on, your fuses are good, your battery will charge and your lights work.