Typical problems with this category of cir-
cuits include the following:
- No operation when the switch is
activated. - Abnormally slow motor operation.
- Frequent tripping of an overcurrent
protection device (such as a circuit
breaker or fuse).
- Frequent tripping of an overcurrent
The troubleshooting procedure is summa-
rized in the flowcharts on pages 4 and 5.
4 marine troubleshooting
Confirm integrity of the power
source using a conductance
battery tester (Chapter 2).
Test both the control side of the
circuit (from the activation
switch to the relay or solenoid
that activates the high-current
side of the circuit) and the
high-current side, with or without
available power.
If the power source is
OK, measure voltage
drop using a
diagnostic meter
(Chapter 2).
If the power source is
not OK, recharge or
replace the batteries.
Check power source integrity with a multimeter, followed by a carbon pile load test of the battery’s ultimate
condition (not possible with sealed batteries). If OK, use a multimeter to trace the entire circuit, separately
measuring each leg of the circuit, recording the voltage readings, and calculating acceptable voltage drop.
NEW METHOD
OLD METHOD
Slow motor
or no motor
operation.
SYMPTOM
High-Amperage Motor Circuits
Confirm the integrity of
the power source using
the conductance
battery tester.
The problem may be a
tripped breaker or fuse.
Remember these devices
trip for a reason; simply
replacing a fuse may not
solve the problem.
Check current draw with
an amp clamp and
compare to the fuse or
breaker rating. Also
consider a locked rotor
condition. Review
Chapter 11 to learn
more.
To determine current draw, connect an ammeter in series; in many cases with higher-current-draw circuits, a
resistive shunt is required. Making these temporary, hard-wired connections often takes considerable time.
NEW METHOD
OLD METHOD
No operation
when the switch
is activated.
SYMPTOM
Low-Amperage Motor Circuits (1)