Troubleshooting Guide - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC

Troubleshooting guide

Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
Major physical or electrical
damage is evident when the
sheet metal covers are
removed.
The engine will not return to
low idle when the welding and
auxiliary loads are removed.
The engine will NOT go to high
speed when a load is applied to
the welding output terminals.
The engine does go to high
speed when a load is applied to
the AC auxiliary power
receptacles.
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the
Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS
1. Contact your local
authorized Lincoln Electric
Service Facility.
1. Make sure the idler control
switch is set to the "Auto"
position.
2. Make sure both welding and
auxiliary loads are removed.
1. Check welding cables for
loose or faulty connections.
Classic® 300 MP Service Manual
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Contact the Lincoln Electric
Service Department at 1-888-
935-3877.
1. Check the idler control
switch and associated leads for
loose or faulty connections.
See the Wiring Diagram.
2. Perform the Engine Fuel
System Voltage Test Procedure
(ECU Test).
3. Perform the Control Board
Test Procedure.
1. Check the yellow and white
leads between the control
board and the DC generator
brushes. See Wiring Diagram.
2. Perform the Control Board
Test Procedure.
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