TM 9-4940-568-20
2-112
Table 2-19. Wire Feeder Welder Troubleshooting (CONT).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
8. WIRE FEEDS, CONTACTOR DOES NOT CLOSE, AND WELDING WIRE IS NOT HOT –
THERE IS NO ARC.
Check contactor (K1), terminal strip (TB1), and plug J1 on the 12 VDC driver p.c. board for loose or faulty
connections.
Check for a damaged or blow fuse on the 12 VDC driver p.c. board.
If this fuse has blown, the contactor or gas valve is most likely shorted and should be
checked (and replaced if necessary) before replacing the fuse.
With the contactor (K1) wires disconnected from the terminal strip (TB1), measure the resistance of the
contactor coil. The resistance should be between 3 to 10 ohms.
If not, replace the contactor (K1).
Replace the 12 VDC driver p.c. board if necessary.
9. WIRE DOES NOT FEED WITH INCH SWITCH DEPRESSED.
Check inch switch (S3) and terminal strip (TB1) for loose or faulty connections.
Check for defective inch switch (S3).
Make sure the power source output voltage is less than 140 VDC.
10. GAS DOES NOT FLOW WITH PURGE SWITCH DEPRESSED.
Check purge switch (S4) and terminal strip (TB1) for loose or faulty connections.
Check for defective purge switch (S4).
11. METERS DO NOT FUNCTION.
Check meters (M1 and M2) and plug J2 on the motor control p.c. board for loose, faulty, or reversed connections.
