On Fri, 13 Dec 2013 20:15:07 -0600, "Irreverent Maximus"
wrote:


wrote in message news
And you forgot something else too. If there is no load connected,
there is NO voltage drop. E=IxR. The voltage drop is E. The
resistance of the conductor is R. If the current is 0, it doesn't
matter WHAT the resistance is, there can be no voltage drop, so
whether the voltage is flowing directly to the switch, or through the
load to the switch, the voltmeter will read exactly the same.



My assertion is with a load connected. Maybe I did not explain it
correctly. The allowable drop for branch circuits is 2% (3% in some
locations).

A common practice for ferreting out issues with motor starters is to
measure the voltage across the input and output of each pole. Though,
this is primarily with poly-phase systems. Reading a voltage indicates
a termination/contact problem.
Same thing a mechanic does when looking for starting/charging/other
electrical problems on a car. Check voltage drop from - battery post
to engine block with starter cranking to check integrety of the ground
circuit - then across every connection if there is a problem until the
high resistance is found - and the same on the positive (load) side.
Same thing in the charging system, lights, heater, etc.