I've gotten different answers from neighbors. I'm wiring up lights for my towable. I noticed that when using a light tester probing say the running light prong of the plug ( the plug on the back of the coach) I have found I can ground to any of the other prongs in the plug (brake, turn signal etc) and use it as a ground.
Is this OK?
I thought the other prongs would be for supply power to their respective lights and not go to ground at all. Thanks for your input.