Lincoln Electric Classic 300 MP Service Manual page 104

LINCOLN ELECTRIC
9. Using a slotted screwdriver, remove the screw securing the negative lead to contactor CR2. See
Figure F.62. See Wiring Diagram. Label and disconnect the negative lead.
10. Label and disconnect leads 630 and 631 from the top terminals of contactor CR2. See Figure F.62.
See Wiring Diagram.
11. Label and disconnect leads 633 and 634 from the quick-connects of contactor CR1. See Figure F.62.
See Wiring Diagram.
12. Using a slotted screwdriver, remove the four screws securing contactor CR1 to the CV box. See
Figure F.63.
13. Using a 11/16" nutdriver, remove the two nuts securing each of the heavy leads to the top terminals
of contactor CR1. Remove the nuts one at a time. See Figure F.62. See Wiring Diagram.
14. Carefully lift the contactor away from the CV box and slide the leads off of the top terminals of
contactor CR1.
15. Using a hammer and slotted screwdriver, loosen the three nuts securing the cord grip connectors to
the CV box. See Figure F.62.
16. Carefully route the leads and cables thru the cord grip connector and out of the CV box. See Wiring
Diagram. The CV box can now be removed.
17. Using a 3/8" nutdriver, remove the two screws securing the finger guard panel to the machine. See
Figure F.64.
18. Label and disconnect plugs J12, J6, J7, J1 and J2 from the control board. See Figure F.65. See Wiring
Diagram.
19. Using a 3/8" nutdriver, remove the two screws and washers securing the control PCB mounting
bracket to the fuel tank rail.
20. Cut cable ties as necessary to remove the control board assembly.
21. Carefully remove the control board assembly out of the machine.
22. Using a 1/2" nutdriver and 1/2" open-end wrench, remove the six nuts securing the heavy leads to
the terminals of the selector switch. See Figure F.66. See Wiring Diagram. Label and disconnect
the leads from the selector switch.
23. Using a 3/4" nutdriver and 3/4" open-end wrench, remove the bolt and nut securing the three leads
to the positive output terminal. See Figure F.67. See Wiring Diagram.
24. Using a 3/8" nutdriver, remove the three screws securing the finger guard panel to the machine.
See Figure F.67.
25. Label and disconnect the engine control unit (ECU) connector from the engine control unit (ECU).
See Figure F.68. See Wiring Diagram.
26. Label and disconnect plug J51 from the coolant temperature gauge. See Figure F.68. See Wiring
Diagram.
27. Label and disconnect plug J52 from the fuel/hour meter/LED gauge. See Figure F.68. See Wiring
Diagram.
28. Label and disconnect plug J53 from the oil pressure gauge. See Figure F.68. See Wiring Diagram.
29. Label and disconnect lead 203A from the 15 amp fuse holder on the lower control panel. See Figure
F.68. See Wiring Diagram.
30. Label and disconnect lead 602C from the exciter field diode on the lower control panel. See Figure
F.68. See Wiring Diagram.
31. Label and disconnect lead 810 from the circuit breaker CB2 on the lower control
F.68. See Wiring Diagram.
Classic® 300 MP Service Manual
panel. See Figure
99