Miller Millermatic 350P Technical Manual page 67

Always perform pre-power troubleshooting before applying power to unit (see Section 8).
RC13
RC64
RC66
Millermatic 350
1 +2.5 to 22 volts DC with respect to RC13-3, spool gun trigger closed, and min to max of spool gun wire
feed speed
2 Not used
3 +2.5 to 22 volts DC with respect to RC13-1, spool gun trigger closed, and min to max of spool gun wire
feed speed
1 Less than 1 ohm with respect to RC64-2
2 Less than 1 ohm with respect to RC64-1
3 0 ohms with respect to RC64-4
4 0 ohms with respect to RC64-3
1 +26 volts DC
2 Ground for +5 volts DC with respect to RC66-3
3 +5 volts DC with respect to RC66-2
4 Not used
5 Ground for +5 volts DC with respect to RC66-6
6 +5 volts DC with respect to RC66-5
TM-1327 Page 63