Cub Cadet 4 x 4 Volunteer - Manual (Page 304)

Chapter 9 - Electrical
300
Ammeters and specialized charging system testers
• Inductive ammeters are available in many forms.
Some are as simple as a gauge to be held
against the circuit in question when it is ener-
gized. See Figure 9.53.
• There are two primary reasons to measure
amperage:
To check the out-put of a charging system or bat-
tery and to check the performance of a compo-
nent that draws a substantial flow of
power...typically a motor or clutch.
• Briggs and Stratton sells a DC Shunt that con-
verts amperage into a reading on the millivolt
scale of a DVOM. Briggs and Stratton part #
19359 covers low amperage systems, while part
# 19468 tests higher amperage systems.
See Figure 9.54.
• Usage of the DC Shunt tool is detailed in the
1995 and 1999 editions of their Update Seminar
materials.
NOTE: The operating principle is based on
Ohm’s Law, as described earlier in this section.
• Kohler makes a proprietary Rectifier/Regulator
tester (Kohler Part Number 25 761 20 and the
up-dated version: 25 761 20-S). This tester
works on Kohler regulator / rectifiers and the
company claims it works on similar systems from
other companies. See Figure 9.55.
• Instructions are included with the Kohler tool
(TT480-A)
Testing the charging system:
• Quick and dirty test: check voltage across the
battery posts using a DVOM set to read D.C.
voltage with the engine turned-off. It will read
battery voltage...typically around 12 V.
Start the engine and repeat the voltage mea-
surement. The system voltage should rise,
reflecting the out-put of the charging sys-
tem...typically in the range of 12.5 - 14.5 V.
If the voltage does not rise, or rises significantly
above this threshold, there is a problem with the
charging system that needs to be identified
using more in-depth techniques.
NOTE: If system voltage is beyond roughly 15.7
volts, it is over-charging and there is a problem
with the voltage regulator / rectifier.
• To identify a specific charging system problem,
isolate the components of the system and check
their performance individually.
Figure 9.53
DVOM with inductive
ammeter feature
Inductive ammeter
Figure 9.54
To negative
battery post
Connect to
battery end of
ground cable
DVOM on
300Mv
scale
calibrated
resistance:
creates
amperage
reading
Figure 9.55