4)5VDC Output Checks: Control Switch (open contacts for icemaking, closed contacts for drain), GMPR (terminals 3 & 5), MBC, and F/S. When checking 5VDC control voltage, always place the red positive test lead from the multimeter to the white K5 connector pin closest to the red K4 connector. See Fig. 2. Then place the black negative test lead from the multimeter to the corresponding pin to complete the 5VDC check.
| Red positive test lead to white | 5VDC | Black Negative |
| K5 connector pin closest to |
| |
| red K4 connecotor | | Test Lead |
| Red Positive | Multimeter | |
| Test Lead | |
| | |
Fig. 2
Control Switch white/black (W/BK)
Yellow Jumper (Y)
Gear Motor Protect Relay
(terminals #3 and #5) white/orange (W/O)
Control Board K9 Connector
a. Control Switch–K9 connector pins #1 and #2 white/black (W/BK) wires: 5VDC is present from the white K5 connector pin closest to red K4 connector to the K9 connector pin #1 white/black (W/BK) wire at all times. If 5VDC is not present, CB is bad and must be replaced. When the control switch is in the "ICE" position, the control switch contacts are open. 0VDC is present from the white K5 connector pin closest to red K4 connector to the K9 connector pin #2 white/black (W/BK) wire. When in the "ICE" position, 5VDC is present from the K9 connector pin #1 white/ black (W/BK) wire to pin #2 white/black (W/BK) wire. When the control switch is in the "DRAIN" position, the control switch contacts are closed. 5VDC is present from the white K5 connector pin closest to red K4 connector to the K9 connector pins #1 or #2 white/black (W/BK) wires. If 5VDC is not present CB is bad and must be replaced. 0VDC is present from the K9 connector pin #1 white/black (W/BK) wire to pin #2 white/black (W/BK) wire.
b. Gear Motor Protect Relay (GMPR)–K9 connector pins #5 and #6 white/orange (WO) wires: When GMPR terminals 3 and 4 are open (GMPR de‑energized), 5VDC is present from the white K5 connector pin closest to red K4 connector to the K9 connector pin #5 white/orange (W/O) wire. If 5VDC is not present, CB is bad and must be replaced. When GMPR terminals 3 and 4 are closed (GMPR energized), 5VDC is present from the white K5 connector pin closest to red K4 connector to the K9 connector pins #5 and #6 white/orange (W/O) wires. Also check from the
K9 connector pin #5 white/orange (W/O) wire to K9 connector pin #6 white/orange (W/O) wire. If 0VDC is present, GMPR terminals 3 & 5 are closed. If 5VDC is present, GMPR terminals 3 & 5 are open and CB may be in an 8-beep alarm. See "II.C.2. LED Lights and Audible Alarm Safeties."
