MTD 700 Series Professional Shop Manual page 143

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Figure 7.56
Figure 7.57
A similar ground-side test on a mower with a slow-
cranking starter motor can be conducted between the
engine block and the negative battery post.
See Figure 7.56.
1. With the starter engaged, this machine exhibited a
voltage-drop reading of 0.312 volts, indicating a poor
ground connection.
2. Individually, these readings should lead a technician
to inspect the connection between the solenoid and
the ground path on the first mower (e.g. mounting
hardware, green wire with eyelet beneath head of
solenoid mounting bolt), or the engine and the frame
on the second mower (e.g. loose or rusty engine
mounting bolts).
3. If both of these readings were found on the same
mower, a common point in the system would be the
primary suspect (e.g. poor connection between nega-
tive battery cable and frame).
Applying this principle to the positive side of the system:
IMPORTANT: Ultimately, all positive current will find
its way from the positive post of the battery to the
negative post.
1. To check hot-side voltage drop: set-up a multi meter
to measure 12V DC. See Figure 7.57.
2. Make a good electrical connection between the red
(+) probe and the positive post on the battery.
3. Make a good electrical connection between the black
(-) probe and the suspect point of the circuit.
4. Power-up the circuit in question.
5. The voltage that shows-up on the meter is the power
that is not following the intended path back to the
negative battery post.
Electrical
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