46
A.C. OUTPUT
YELLOW
16 Amp Alternator System with External Regulator
CHECKING THE SYSTEM:
An open circuit D.C. voltage check cannot be made with this system. If a known
good battery fails to maintain a charge, proceed to make an A.C. voltage test.
Disconnect the red D.C. output connector at the wiring harness and connect the probes from an A.C. voltmeter
to the wire terminals at the regulator-rectifier.
With the engine running, minimum values should read:
2500 R.P.M. - 21 Volts A.C.
3000 R.P.M. - 26.5 Volts A.C.
3600 R.P.M. - 31.0 Volts A.C.
22
If the minimum values are noted, the alternator is
operating properly. If less than the above values are
noted, the alternator is defective.
VOLTAGE REGULATORS
If a known good or load tested battery fails to maintain
a charge, the charging system and the regulator can
be checked using a voltmeter. Set the voltmeter on
the 0-20 Volt D.C. scale and connect the probes
across the battery terminals. Note the battery voltage.
Start the engine, the voltage reading should increase
from the noted battery voltage but not exceed 15 Volts
D.C. If no voltage increase is noted, proceed to make
an A.C. voltage check using the applicable procedure.
If the battery voltage exceeds 15 Volts D.C., or the
proper minimum A.C. voltage is noted during the
check, replace the regulator (diag. 23).
FUEL SHUT-DOWN SOLENOIDS
If the engine is running, the solenoid can be checked
by removing the electrical plug-in at the base of the
solenoid. Almost immediately the engine should shut
down, if not replace the solenoid.
Test the solenoid off the carburetor by applying 12
volt D.C. from the battery positive terminal to the (or
one) solenoid terminal. Connect a jumper wire from
the metal housing (or other terminal) to a negative
battery terminal. The plunger should retract the full
travel distance. Disconnect the negative jumper lead
and the plunger should return to the extended position.
Replace if necessary (diag. 24).
A.C.
D.C. OUTPUT - RED
SOLENOID
GREEN
LIGHT
SWITCH
AMMETER
MAGNETO
GROUND
BATTERY
REGULATED
D.C. OUTPUT
FUSE
YELLOW
RED
NOTE: D.C. OUTPUT MUST BE DISCONNECTED TO
PERFORM A.C. OUTPUT TEST.
10 Amp A.C. Alternator
CHECKING THE SYSTEM:
Unplug the connector at
the wiring harness supplied by the OEM. Proceed to
make an A.C. output check. Place one lead of the
A.C. voltmeter on the center plug of the connector.
Place the other lead to engine ground (diag. 22).
With the engine running, minimum values should read:
2500 R.P.M. - 16.0 Volts A.C.
3000 R.P.M. - 20.0 Volts A.C.
3300 R.P.M. - 22.0 Volts A.C.
If less than above output, the alternator assembly is
defective. See Chapter 9 for "Disassembly
Procedure".
23
24
DOUBLE
SINGLE
www.mymowerparts.com
For Discount Tecumseh Engine Parts Call 606-678-9623 or 606-561-4983