Electrical System
95
Voltage Drop Test
To review:
•
Ohm’s law states that it takes voltage to push
current through a resistance.
•
Kirchhoff’s voltage law states that the sum of all
the voltage drops equals the source voltage.
•
Combining those two laws, we see that any
restriction in a circuit (e.g.: loose connector
damaged wire, or corroded terminal) will use up
some voltage as the current is pushed through.
•
A voltage drop test is a way of looking for that
voltage.
•
Because electricity needs to complete a full cir-
cle (circuit), voltage drop tests are useful on
both the positive or the negative side of the sys-
tem.
•
This text will begin diagnosis from the negative
side. Bad grounds are responsible for as many
electrical failures as the positive side of the sys-
tem, yet the ground side is frequently neglected
by technicians. See Figure 7.41.
NOTE:
Ultimately, all current will find its way from the negative battery post to the positive battery post.
To check ground-side voltage drop: set-up a multimeter to measure 12V DC.
1.
Make a good electrical connection between the black (-) probe and the negative post on the battery.
2.
Make a good electrical connection between the red (+) probe and the suspect point of ground.
3.
Power-up the circuit in question.
4.
The voltage indicated on the meter is the voltage that is being used to pass current through a resistance in the
circuit.
5.
Voltage drop on a good circuit should be less than 0.1 volts. A voltage drop reading on the meter of greater
than 0.2 volts indicates a fairly substantial problem that demands attention.
•
As an example, if the starter solenoid does not
engage properly, check for voltage drop
between the ground point for the starter sole-
noid and the negative post on the battery.
See Figure 7.42.
•
With the starter engaged, this machine exhib-
ited a voltage-drop reading of 0.308 volts, indi-
cating a poor ground connection.
Figure 7.41
Figure 7.42
www.mymowerparts.com
For Discount Cub Cadet Parts Call 606-678-9623 or 606-561-4983
Содержание RZT-S
Страница 2: ...www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 6: ...IV www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 28: ...Z Force S 22 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 52: ...RZT S 46 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 66: ...RZT S 60 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 108: ...RZT S 102 Schematic 7 211 725 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 126: ...RZT S 120 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 134: ...RZT S 128 www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...
Страница 135: ...www mymowerparts com For Discount Cub Cadet Parts Call 606 678 9623 or 606 561 4983 ...