Tecumseh ECV105 Technician's Handbook page 55

NOTE: ON OLDER POINT IGNITION SYSTEMS, THE
A.C. OUTPUT LEADS ARE BLACK AND RED.
3 Amp D.C. Alternator System - Rectifier
Panel
This 3 amp system is readily identified by the rectifier
panel in the circuit. The panel includes two diodes and a
fuse for overload protection. The rectifier panel does not
regulate the output of this system.
CHECKING THE SYSTEM: Check the fuse to determine
if it is good. A continuity light or ohmmeter can detect a
faulty fuse. Replace with a six (6) amp fuse if necessary.
Determine if the diodes are functioning properly. A
continuity light may be used to check diodes. (diag. 17).
When replacing the diode in the rectifier panel, locate
the undercut on one end of the diode and match it to the
detent on terminal clip of the rectifier panel.
Test the D.C. output of the rectifier panel as follows:
Disconnect the battery lead from the terminal of rectifier
panel. Use D.C. voltage meter probe on + battery terminal
as shown in the diagram (diag. 18). Connect negative
lead to engine ground.
Minimum values should read:
2500 R.P.M. - 12.0 Volts D.C.
3000 R.P.M. - 14.0 Volts D.C.
3300 R.P.M. - 16.0 Volts D.C.
3600 R.P.M. - 18.0 Volts D.C.
If these minimum readings are noted, the system is okay.
Check for bad battery, ammeter, wiring, etc.
If less than above reading, proceed to make an A.C. output
check. With the battery lead disconnected from rectifier
panel, probe the A.C. terminals with the voltmeter on the
A.C. scale (diag. 19).
Minimum values should read:
2500 R.P.M. - 24.0 Volts A.C.
3000 R.P.M. - 29.0 Volts A.C.
3300 R.P.M. - 32.0 Volts A.C.
3600 R.P.M. - 35.0 Volts A.C.
If less than above output, generating coil assembly is
defective. See Chapter 9 for "Disassembly Procedure".
NOTE: There is no regulator in this system. The total
output of the two diodes is three (3) AMPS. If the battery
is overcharging (boiling and bubbling), reduce the D.C.
input by one-half by removing one of the diodes.
-
GREEN
YELLOW
PROBE
RECTIFIER PANEL
MOUNTED ON
ENGINE
FUSE
+
17
D.C. VOLTMETER
YELLOW
FUSE
-
+
TO ENGINE
GROUND
18
A.C.
VOLTMETER
19
51