TROUBLESHOOTING & REPAIR
F-62 F-62
RANGER 305D
Return to Section TOC Return to Section TOC Return to Section TOC Return to Section TOC
Return to Master TOC Return to Master TOC Return to Master TOC Return to Master TOC
CHOPPER MODULE FUNCTION TEST (continued)
FIGURE F.17– POWER MODULE CONNECTIONS
TEST PROCEDURE
1. Perform the Case Cover Removal
Procedure.
2. Make sure that there is nothing plugged into
either of theAmphenol receptacles.
3. Place idle switch in the “HIGH” position.
4. Place the mode switch in the “CC-STICK”
position.
5. Place the Welding Terminal switch in the
“REMOTELYCONTROLLED” position.
6. Start the engine and allow it to stabilize at
high idle RPM.
7. Check for 80 to 100 VDC at terminals B1- to
B2+ and B4- to B5+ of the chopper module.
See wiring diagram and figure #1.
8. If the correct DC voltage is not present at ter-
minals B1- to B2+ and B4- to B5+, check for
damaged conductors or faulty connections
between the chopper module, the output rec-
tifier,and the stator weld winding. SeeFigure
F.17. See the wiring diagram. Perform the
Stator Voltage Tests, and the Output
Rectifier Test.
9. If the correct voltage is present at terminals
B1- to B2+ and B4- to B5+ of the chopper
module, check for DC voltage at the chopper
module terminals B2+ to B3-, and B5+ to B6-
, If significant voltage is present, disconnect
leads #23 and #25 from the chopper module
PC board. If voltage is still present, the cop-
per module is shorted and should be
replaced.
10. If the voltage drops to 0 VDC after the #23
and #25 leads have been disconnected, the
control PC board is driving the chopper mod-
ule when it should not be doing so.
Reconnect the #23 and #25 leads and per-
form the Weld Control Board Gate Drive
Test.
11. Reconnect leads #23 and #25, and place the
Welding Terminalswitch in the “WELD TER-
MINALS ON” position.
12. Check for about 58 VDC between Chopper
Module TerminalsB2+ to B3-, and B5+ to B6
and between the welder output terminals.
See Figure F.17. See the wiring diagram.
B1
B2
B3
B4
B5
B6
SL302
SL301 SL14
SL13
B7
B8
HLW9
HLW4
HLW6
HLW8
HLW5
HLW11