SECTION 7 - GENERAL ELECTRICAL INFORMATION & SCHEMATICS
7-4
31215079
Continuity Measurement Over Long Distances
When trying to determine continuity of a harness or
wire, longer than the reach of standard instrument
leads, is possible to perform the check without exces-
sively long leads. Using the other wires in the harness
one can determine the condition of a particular wire in
the harness.
Requirements:
• Harness with at least three separate wires including
the wire under test.
• These wires must be able to be isolated from other
wires, etc.
• Jumper or method to connect contacts on one side
of harness.
• Meter that can measure resistance or continuity.
Procedure
Test multimeter leads resistance. Subtract this value
from the measured resistance of the wires to get a more
accurate measurement.
Consult the circuit schematic to determine which wires
to use in addition to wire under test, here called wire #1
and wire #2, and how to isolate these wires. These wires
should appear in the same connectors as the wire under
test or are within reach of the jumper.
1. Disconnect all connections associated with the wire
under test and the two additional wires. If harness is
not completely isolated disconnect battery terminals
also, as a precaution.
2. Measure continuity between all three wires, the wire
under test, wire #1 and wire #2. These should be
open. If not, repair the shorted wires or replace the
harness.
3. On one side, jumper from contact of wire #1 and wire
#2.
4. Measure continuity between wire #1 and wire #2. If
there is continuity, both wires are good and can be
used for this test. If there is not continuity, either wire
could be bad. Check connections and measurement
setup. Redo measurement. If still no continuity, repair
wires or consult schematic for other wires to use for
test.
5. Jumper from wire under test to wire #1.
6. Measure continuity. If there is continuity, the wire
under test is good. Resistance of a wire increases as
the length increases and as the diameter decreases.
One can find the continuity of two wires, here #1 and #2,
at once by following steps 1 through 4. If there is a prob-
lem the third wire is used to troubleshoot the other
wires. To find the problem, start at step 1 and use the
entire procedure.
7.3
APPLYING SILICONE DIELECTRIC COMPOUND
TO ELECTRICAL CONNECTIONS
Silicone Dielectric Compound must be used on all elec-
trical connections for the following reasons:
• To prevent oxidation at the mechanical joint
between male and female pins.
• To prevent electrical malfunction caused by low level
conductivity between pins when wet.
Use the following procedure to apply Silicone Dielectric
Compound to the electrical connectors.
1. To prevent oxidation and low level conductivity, sili-
cone dielectric grease must be packed completely
around male and female pins on the inside of the
connector after the mating of the housing to the
header. This is easily achieved by using a syringe to
fill the header with silicone dielectric compound, to a
point just above the top of the male pins inside the
header. When assembling the housing to the header,
it is possible that the housing will become air locked,
thus preventing the housing latch from engaging.
2. Pierce one of the unused wire seals to allow the
trapped air inside the housing to escape.
3. Install a hole plug into this and/or any unused wire
seal that has silicone dielectric compound escaping
from it.
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