Tecumseh ECV105 Technician's Handbook page 54

TEST NO. 2 - Connect the positive probe of meter to red output lead. Connect the negative probe of meter to both A.C.
terminals and black output lead.
Connect the negative probe of meter to black output lead. Connect the positive probe of meter to both A.C. terminals
and red output lead.
If the D.C. adaptor is not defective and a known good battery fails to hold a charge, then perform an A.C. output
voltage test.
NOTE: PRIOR TO AUGUST 1992, THE BLACK WIRE WAS BROWN.
CHECKING THE SYSTEM: To check the system, disconnect the D.C. adaptor from the add-on alternator. Connect a
No. 4414, 18 watt bulb in line with each terminal in the alternator. Start engine and test circuit using an A.C. voltmeter
as shown (diag 14).
With the engine running, minimum A.C. voltage values across the bulb should be:
2000 R.P.M. - 8.0 Volts A.C.
3000 R.P.M. - 10.5 Volts A.C.
3600 R.P.M. - 12.0 Volts A.C.
If the minimum values are noted, alternator is okay. If the minimum values are not noted, the alternator or A.C.
connector is defective.
2.5 Amp D.C., 35 Watt Lighting
To check this system follow the meter hook ups at the
right, checking the D.C. negative and D.C. positive first. If
output is below standard listed, pull back protective
coating in front of the diode and check A.C. output. If A.C.
is good check each diode it services as requested see
parts list. (diag. 15)
D.C. value (+) or (-) check. A.C. outputs both sides.
R.P.M. D.C. Volts
2500 - 8.0 Volts D.C.
3000 - 9.5 Volts D.C.
3300 - 10.5 Volts D.C.
3600 - 11.5 Volts D.C.
NOTE: These minimum numbers should be obtained by
your meter and will often be higher.
3 Amp A.C. Lighting Alternator
Models: H & HSK 30- 35, HS & HSSK 40, H &
HSK 50-60, HH50-60, HM & HMSK 70-80-100,
HHM80
Before making any exterior tests, check for an inoperative
switch, shorted wires and burned out headlight and/or
stop tail light. To check out the alternator, check the A.C.
lead to ground (diag. 16).
With engine running, minimum values should read:
2500 R.P.M. - 8.0 Volts A.C.
3000 R.P.M. - 9.5 Volts A.C.
3300 R.P.M. - 10.5 Volts A.C.
3600 R.P.M. - 11.5 Volts A.C.
If the above minimum readings are noted, the alternator
is okay. Check for defective lights, wiring or switches. If
less than the above readings, the alternator is defective.
See Chapter 9 for "Disassembly Procedure".
50
R.P.M. Volts A.C.
2500 - 18 Volts A.C.
3000 - 22 Volts A.C.
3600 - 26 Volts A.C.
TWO DIODES
RED
D.C.
A.C.
HEAD & TAIL LIGHT
STOP LIGHT
TO POSITIVE
D.C.
SIDE OF
BATTERY
D.C. NEGATIVE
OUTPUT LEAD
(BROWN D.C.)
D.C. POSITIVE
OUTPUT LEAD
(RED D.C.)
15
YELLOW
GREEN
YELLOW
IGNITION GROUND
16