Measure the resistance of the bulb alone. Then measure the resistance of the
wires with the bulb in the socket from the circuit breaker or power
connection. If the bulb is, for instance, 12 watts, it draws 1 ampere. If
the wire resistance is 5 ohms in addition to the bulb resistance, you're
looking at a five volt drop in the wires, which is almost the power of the
bulb.

Report the resistances of the wires back to me and I'll walk you through
this.

Magnum

"Seahag" wrote in message
...
So the aft-most two dome lights (12 volt) on a 4 light circuit have been
giving me the blues for a month or so. Intermittant most of the time but
now dead, sort of... Bill replaced the switch on one and they both worked
until he left town...After another day of meters and torn up galley seems
he's getting 13 volts through the wires but it won't light the bulb...He's
thinking there is some sort of resistance somewhere. Any ideas?
Experience? Jokes?? The Taiwanese in their infinite wisdumb epoxied the
wires into the deck beams and cabin sides!!!

Seahag
(Dinner's on before dark!)