In article ,
albee wrote:


Okay, replaced the upper thermostat. Still no reading between L1 and
L3; should there be? Still 120 from each pole to ground.
No reading between the upper element contact screws, so no power is
getting there. Another bad thermostat? I'm stumped (but that doesn't
take much).

You can't fix something until you understand it. The VOM is one of the
strangest tools ever invented, in that it gives people who don't
understand a circuit the idea that they can troubleshoot it. After all,
they have the tool.

Until you can draw and understand a schematic of the system, the VOM is
about as useful as a screen door on a submarine. You poke it around here
and there, and you think it's giving you information, but it isn't. It's
just giving you a useless number.

So step one, draw the circuit. A guy who already understands the system
can skip this step, and that's why you see an electrician just probing
here and there with a meter. But in his head, that circuit is either
clear as day, or becoming clear as he probes.