If it is for the external connection, then it is there to prevent the
external power from activating the master or external power solenoid
from energizing if the external source polarity is reversed.
Michelle

wrote:

Another good idea, but the schematic has rather clearly shown the
diode/connector setup for the external connection, but has it shown as "optional."
This diode/resistor is in addition to that.

nrp wrote:
: I don't know Cherokee electrics, but does it maybe offer a way to (very
: slowly) charge the battery thru the external service plug?

: My Cessna 172M has a funny diode-resistor circuit like that in the
: battery circuit in which that's the only reason I can see for it. It
: is not described in the POH or even the service manual. Otherwise with
: a completely dead battery, if I used the ground service plug to start
: it, there still wouldn't be anything in the battery to initialize the
: alternator.

: Flyback diodes don't usually have a resistor in series with them.