Advanced Marine Electrics and Electronics Troubleshooting A Manual for Boatowners and Marine Technicians

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).
  
  
  
  

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)