Originally Posted by gemini5362
At this point you need an ohm meter and someone that knows how to use it. If you do good if not get someone that does to help you.
I'm Mike Sokol, author of the No~Shock~Zone articles on electrical safety. Here's my tutorial on how to test extension cords with an ohmmeter. RV Electrical Safety: Part XI
Note that ANY appliance inside your RV with a grounded power plug can leak up to 3.5 mA of current to ground and still be UL approved, while ungrounded appliances can leak up to 0.75 mA of ground fault current. So if your shore power connection has a broken ground (extension cord, dog-bone adapter, etc..) then any appliance such as your microwave or inverter can raise the voltage on the skin of your RV up to 120-volts. Also, these leakage currents are additive, so a GFCI can be tripped by several appliances leaking UL approved levels. Another thing to watch for are Surge Strips, which can easily leak 3 or 4 mA of current to ground. So a single surge strip might not trip a GFCI, but two of them plugged into the same circuit could cause random tripping. So GFCI's will protect you, but sometimes are fooled with multiple appliances leaking normal amounts of ground fault current.
Here's a thread on PopUpPortal where I show how to build a ground fault current tester using a brake light bulb and some alligator clips. Possible Bad Converter?? - LONG
I've not formally published an article on this test yet, but the thread details the testing procedure which if far superior to any ohmmeter test since it applies 2 amps of fault current to your ground path.
Let me know how you make out.
No Shock Zone