Lincoln Electric RANGER 8 SVM107-B Service Manual page 66

F-26
OUTPUT RECTIFIER BRIDGE TEST (continued)
+
Diode
Output rectifier
Bridge Assembly
TEST PROCEDURE
1. Remove the spark plug wires to prevent
accidental engine kickback or starting.
2. WIth the 5/16" nut driver, remove the 6
sheet metal screws from the case top.
3. Remove the rubber gasket (cover seal) from
the lift bail.
4. Remove the fuel cap. The rubber gasket for
the fill tube will come off with the case top.
5. Remove the case top, then replace the
fuel cap.
6. With the 5/16" nut driver, remove the 5
screws holding the right case side.
7. Remove the right case side by lifting up and
out.
8. Conduct the test with the gasoline engine
OFF.
9. Locate the Output Rectifier Bridge behind
the machine case front.
TROUBLESHOOTING & REPAIR
FIGURE F.5 – LOCATION OF OUTPUT RECTIFIER LEADS
Pigtail
Machine Front
RANGER 8
-
10. With the 7/16" wrench or socket wrench
and 6" extension, remove the nuts and
washers holding the diode bridge pigtails
and the heavy current-carrying leads to
the studs located in the middle of the rec-
tifier assembly. Note their locations and
the order of fasteners for reassembly.
11. Electrically isolate the diode pigtails by
bending them back into "free air."
12. With an ohmmeter or diode tester, check
each of the four diodes from their pigtails
to their respective heat sinks. See Figure
F.5.
13. Reverse the tester leads and check the
diodes again. Diodes should have a low
resistance in one polarity and a very high
resistance in the opposite polarity.
14. Replace any "shorted" or "open" diode as
the tests indicate.
15. Reconnect the diode pigtails and heavy
leads to their respective studs.
16. Reinstall the case side, case top, fuel cap,
lift bail gasket and spark plug wires.
F-26
Ohmmeter Probes