Lincoln Electric RANGER 305 D Service Manual page 102

RANGER 305D
10. If the meter reading indicates battery voltage,
about 12 to 14 VDC, the rotor may be open, or
the brushes may be faulty or not making proper
contact with the slip rings. Perform the Rotor
Resistance Test, and Brush and Slip Ring
Service Procedure.
11. If the voltage measures about 3 to 5 VDC, the
generator is not building-up to normal output
even though the flashing circuit appears to be
functioning normally. This condition could be
caused by one of several failed components or
connections. Continue with the following test.
12. Check the field bridge rectifier, (D3) and
capacitor (C3); also check the wiring and
terminals connecting them. See the wiring
diagram.
Perform the Rotor Resistance Test.
13.
14. Perform the Stator Short Circuit and Ground
Test.
15. When the Stator short circuit and ground test has
been completed, reconnect leads #7 and #9 to
the field bridge rectifier, (D3). All other stator
leads should remain disconnected and isolated
at this time.
16. Be sure that there are no leads of any kind
across any of the stator windings, except the #7
- #9 winding. Examine stator wiring for damage,
pinched leads, chafed insulation, etc. If
ROTOR VOLT GE TEST (continued)
F 45
necessary, disconnect and isolate the stator
output leads as close to the starter as possible.
See wiring diagram.
17. All of these disconnected leads should be
insulated, and/or positioned so they cannot come
in contact with any other wiring or chassis
ground and cannot be damaged by moving parts
when the engine is running.
18. Re-start the machine and measure the rotor
voltage.
19. If rotor voltage continues to read significantly
lower than 50 VDC, the Stator is probably
defective and should be replaced.
Note: The field bridge rectifier and field capacitor may
appear to function normally when tested independently, but
may malfunction when placed under the stress or normal
operation. For this reason, It is recommended that the
bridge rectifier and the capacitor be replaced with known
good components before replacing the stator.
TROUBLESHOOTING & REPAIR