Tecumseh ECV100 - 120 Technician's Handbook page 59

7 Amp Alternator System Regulator-
Rectifier Under Engine Block Housing
Models: H50-60, HH50-60, HM70-80-100,
HHM80, TVM125-140-170-195-220
In this system, the regulator and rectifier are combined in
one solid state unit mounted under the blower housing of
the engine.
Various types of regulator-rectifiers have been used on
different applications. Test procedures for all types are the
same. However, regulator styles are not interchangeable
(diag. 28).
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.
To do this, the blower housing must be removed, and the
regulator-rectifier must be brought outside of the blower
housing.
Keep the A.C. leads attached to the regulator-rectifier. Install
the blower housing with the regulator-rectifier outside the
housing. With an A.C. voltmeter probe the regulator as
shown (diag. 29)
CAUTION: AT NO TIME SHOULD THE ENGINE
BE STARTED WITH THE BLOWER HOUSING
REMOVED.
With engine running, minimum A.C. voltage from lead to
lead should be:
2500 R.P.M. - 16.0 Volts A.C.
3000 R.P.M. - 19.0 Volts A.C.
3300 R.P.M. - 21.0 Volts A.C.
3600 R.P.M. - 23.0 Volts A.C.
If the minimum readings are noted, the alternator is okay.
If the system fails to charge a known good battery, the
regulator-rectifier must be defective.
10 Amp Alternator System - Regulator-
Rectifier-External to Engine
In this system, the regulator and rectifier are combined in
one solid state unit.
CHECKING THE SYSTEM: To check the system,
disconnect the D.C. or B+ wire at the switch end and
measure D.C. voltage between the lead and ground (diag.
30).
With the engine running, minimum values should read:
2500 R.P.M. - 13.0 Volts D.C.
3000 R.P.M. - 16.0 Volts D.C.
3600 R.P.M. - 20.0 Volts D.C.
If the minimum values are noted, the system is okay. Check
for defective ammeter, wiring, etc. If less than the above
readings, disconnect the plug from the regulator-rectifier,
and insert the A.C. voltmeter probes in the two outside
terminals (diag. 31).
CAUTION: BLOWER
HOUSING MUST BE
INSTALLED WHEN
RUNNING ENGINE
B+ TERMINAL WIRE
GREEN
(continued on top of next page)
FULL WAVE
HALF WAVE
MAGNETO GROUND - GREEN
D.C. OUTPUT LEAD-RED
YELLOW
HALF WAVE
28
INSERT PROBES INTO
CONNECTOR SLOTS
DO NOT REMOVE
CONNECTOR WIRES
YELLOW
RED
A.C. VOLTMETER
29
REGULATOR/
RECTIFIER MUST BE
GROUNDED
30
31
55