Panel lights breaker pops

wrote:
On Jul 24, 5:50 pm, "Larry D. Cosby" lcosby at knology dot net
wrote:
Common problem on older Cherokee models. Chaffed wiring where it passes thru
bulkheads in wings or fuselage. Isolate one circuit at a time to pinpoint
correct wiring path to look at.


It wasn't the nav lights that were popping the breaker; it was the
panel lights. If there's a short there, they shouldn't come on at all.
The easiest path would be to ground, not through the bulbs. My bet is
a bad breaker, or a corroded or burnt crimp terminal at the breaker.
The breaker's internal contacts oxidize with age and start making
resistance and heat that fools the bimetal thermal strip into popping.
The rheostat (potentiometer) carries only the tiny base current for
the transistor; flickering lights should be the result of a worn pot,
not a popped breaker. Unless, of course, it's a wirewound pot and the
wires are frayed and broken inside. Not likely, though. Wirewound pots
aren't common in the resistances used here and they cost too much.

Dan


My Cessna use a wire wound pot that kept burning out. I took one apart
and was it cheaply made.

--

Regards, Ross
C-172F 180HP
Sold
KSWI