Electrochemical corrosion
67
Checking for leakage from the
electrical system
A simple way of testing the boat’s electrical integrity is
to employ the following procedure:
First check that fuses and circuit breakers are fitted
and intact, that the battery main switches are on, and
that all other switches and appliances are off. Theo-
retically, there should be no current flowing from the
battery. Any flow will indicate a leak.
. To check if any current is leaking.
Lift off the positive battery terminal connector and
connect a 2 volt, 3W test lamp between the positive
terminal and the loosened connector. If there is no
leak, the lamp will fail to light. A faint glow indicates a
small leak, and a bright light means that you have a
more serious leak. You can also use a Voltmeter for
this test. Note that some equipment may consume
current even when it is switched off (clock or radio),
which will cause the lamp to light. Such equipment
must be disconnected.
2. To check how much current is flowing.
Use a multimeter, and set it to read "DC Amps". Con-
nect the red test lead to the battery positive terminal,
and the black lead to the loosened connector. The
meter will now show how much current is leaking. If
you do not get a reading, change to the ’’DC mAmps’’
scale.
3. Double-check to see the resistance in the circuit.
Set the multimeter to Ohms. Connect the black test
lead to the loosened negative connector, and the
red test lead to the loosened positive connector. You
should now see a reading of the resistance of the
circuit.
NOTE! Certain equipment may also cause a current
drain when shut off, such as a radio, clock or auto-
matic bilge pump. This equipment must be discon-
nected.
The rough guide below indicates what these readings
means in practical terms:
• 0.000 Ohm up to open circuit– A next to perfect
circuit, no problems.
• 5.000 Ohm – There is a small leak.
• .000 Ohm – There is a leak that must be found
and corrected.
• 500 Ohms or less – A heavy leak. Disconnect the
battery terminals. Repair as soon as possible.
4. To find the leak.
Charging Oil pressure
With the test lamp connected as step above, loosen
one fuse at a time and put it back again. When you
remove a fuse and the test lamp goes out, then you
have found the circuit that is causing the problem.
Trace the circuit until the fault is found, and repair it.
Summary of Contents for D11 series
Page 1: ...Marine Propulsion Diesel Engines Installation 1 1 D E D5 D16 series ...
Page 2: ......
Page 208: ...206 References to Service Bulletins Group No Date Concerns ...
Page 209: ...207 Notes ...
Page 210: ...208 Notes ...
Page 212: ...7748655 English 11 2007 ...