Horizon Fitness P-1000 Installation Instructions Manual page 20

BEHAVIOR:
RPM drop during pre-flight magneto test is excessive.
P-1000 continuously indicated excessive RPM difference for
right and left magnetos (Greater than allowed for this aircraft).
P-1000 continuously displays "Mag-Drop" indication with un-
stable displayed information.
Erratic or non-stable RPM readings on the P-1000.
RPM becomes unstable at higher engine speeds.
No engine RPM reduction when magneto is grounded by
ignition switch.
P-1000 indicated no RPM. Engine runs and ignition switch is
not shorting magneto.
RPM becomes unstable or inaccurate as engine warms up.
Red or Yellow Status LEDs flicker.
Yellow Status LED is on without either RED LED.
HORIZON INSTRUMENTS, INC. P-1000 INSTALLATION & INSTRUCTION MANUAL
Title:
PROBABLE CAUSE:
Failing ignition system. Probable weak magneto or high-voltage
components (ignition wires, plugs, etc.).
This is a common indication of degradation of one of the two ignition
systems. The ignition system with the lesser RPM may be mis-firing.
P-1000 has an intermittent connection to a magneto (missing signals
at P-1000).
Low magneto power output, bad connection, or bad magneto points.
Suspect point floating or possible ignition coil failure.
Possible hot magneto condition, P-Lead signal is not grounded.
Possible open P-Lead wire or non-functional ignition switch.
P-Lead wires may be "open" or broken.
arriving at switch connection. Power buss ground is floated from
magneto, or P-100 has no connection to magneto ground.
Probable bad magneto points, bad bearing.
Intermittent connection in P-Lead or possible grounding of P-Lead.
Check for loose connection at magneto, bad ignition switch, and
breached insulation on P-Lead wire. Possible bad magneto.
Indicates that the magnetos are not supplying the same number of
pulses (i.e. One for each cylinder).
points or an intermittent connection.
Number:
Magneto signal is not
This generally indicates bad
P103050 E
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