How can I tell if an appliance is grounded?

Question

We're doing some kitchen remodeling in our 100-year-old home and came across some very sketchy wiring hidden in the soffit. There is never any current running through the junction, and because there is only the white wire connected, we suspect that the two wires were spliced together during slapdash renovations earlier in order to ground an outlet/appliance somewhere.

We disconnected the junction and tested all the grounded outlets in the house (not many of 'em here) - nothing has changed, everything's still grounded. How can we test our appliances to see whether they're still grounded or not?

Answer 1

If you have a known good ground nearby (or can get one by using an extension cord), you can check that the appliance plug (if it has one) or its chassis has continuity to ground using a multimeter.

In resistance mode (measuring Ω), you should read 0Ω (or very close).

Note that that will only tell you that it's connected, not that it's adequate for the load: the ground wire should be as big as the hot, because it will have to carry the current if it's ever needed. There's not a way to test that, that I know of, you just have to inspect the wiring. I'd definitely be highly wary of a random wire connected as you've shown being used as a ground.