13
Midtronics B.V. Hoofdveste 6 3992 DG HOUTEN
www.midtronicseurope.com
CHAPTER 7:
CABLE DROP TEST
If the test results for the starter or charging systems indicate
that there may be a problem, you may want to perform the
Cable Drop Test to determine if it is due to worn cables or
bad connections between the battery and the alternator
or starter. Worn cables or bad connections create higher
resistance, which causes a drop across the circuit. The voltage
drop reduces current carrying capability that displays the
same symptoms as a weak alternator or starter and causes
premature battery failure.
There’s no need to run the engine. The Cable Drop Test
uses Midtronics’ conductance technology to send a signal
through the circuit at the component under test. The tester
then simultaneously calculates voltage drop on the positive
(+) and negative (–) sides of any circuit as well as the total
voltage drop. The amperage range for each of the four tests
is 0 to 1000 A. When you change the setting from the factory
defaults, the tester will store your setting in memory for your
next test.
There are three preset tests:
•
BATTERY/CHASSIS GROUND
•
STARTER CIRCUIT
•
ALTERNATOR CIRCUIT
A fourth test, OTHER CIRCUIT, tests other grounds and circuits
against your specified amperage capacity.
The test requires two test lead connections:
•
Battery test leads at the component’s output lead
(the B+ or output screw on the alternator) and
the component’s housing as ground
•
DMM test leads at the battery terminals
NOTE:
The test requires a complete circuit. If
you’re testing a system with a remote solenoid,
you can test from the battery to the solenoid, but
not from the battery to the starter.
To begin, select the Cable Drop Test icon in the Main Menu
and follow the instructions on the display.
IMPORTANT:
For accurate results the battery
should be good and fully charged before you
perform a test.
1.
Type in the USER ID (consisting of two letters).
2.
Select the VEHICLE TYPE.
1
BUS/TRUCK
2
CAR/LCV
Press the NEXT soft key to continue.
3.
Select CIRCUIT: Use the UP/DOWN ARROWS or the nu-
merical keypad to select the Battery Ground Test (if BUS/
TRUCK was chosen this will be Chassis Ground Test).
1
BATTERY GROUND
2
STARTER CIRCUIT
3
ALT CIRCUIT
4
OTHER CIRCUIT
Press the NEXT soft key to continue.
BATTERY/CHASSIS GROUND TEST
The Battery Ground Test measures the voltage drop for the
ground strap.
4.
SET AMPS: Use the UP/DOWN ARROWS or the
keypad to select the rated amperage of the
circuit you are testing. The default is 80 A.
Press the NEXT soft key to continue.
5.
Connect the main clamps (battery test leads) to
the battery and ground: positive (+) clamp to the
battery’s positive post; negative (–) clamp to the
vehicle chassis.
6.
Connect the DMM cable to the battery posts:
positive (+) clamp to the positive post; negative
clamp (–) to the negative post.
For the next few seconds the Tester will display the word
TESTING and a stopwatch while it evaluates the battery
ground.
BATTERY GROUND TEST RESULTS
Battery Ground Test PASS Result
If there is a problem, the decision is CLEAN AND RETEST OR
REPLACE. To print the results, align the Tester’s IR transmitter
with the printer’s receiver, and select the PRINT soft key. To
return to the Main Menu, press the END key.
STARTER CIRCUIT
The Starter Circuit Test measures the voltage drop of the
starter circuit.
3.
SET AMPS: Use the UP/DOWN ARROWS or the
keypad to select the rated amperage of the
starter circuit. The default is 150 A.
Press the NEXT soft key to continue.
4.
Connect the positive (+) clamp of the battery
test leads to the starter’s battery terminal stud.
Connect the negative (–) clamp to the starter’s
housing.
5.
Connect the positive (+) DMM clamp to the
battery’s positive (+) post. Connect the negative
clamp (–) to the battery’s (–) negative post.
For the next few seconds the Tester will display the word
TESTING and a stopwatch while it evaluates the battery
ground.
STARTER CIRCUIT TEST RESULTS
Starter Circuit PASS Result
If there is a problem, the decision is CLEAN AND RETEST OR
REPLACE. To print the results, align the Tester’s IR transmitter
with the printer’s receiver, and select the PRINT soft key. To
return to the Main Menu, press the END key.
ALTERNATOR CIRCUIT
The Alternator Circuit Test measures the voltage drop of the
alternator circuit.
3.
SET AMPS: Use the UP/DOWN ARROWS or the
keypad to select the rated amperage of the
alternator circuit. The default is 80 A.
Press the NEXT soft key to continue.
4.
Connect the positive (+) clamp of the battery
test leads to the alternator’s output stud (B+).
Connect the negative (–) clamp to the alternator’s
housing.
