Bunn DUAL - Troubleshooting Brewer Noises and Beverage Quality; Weak Beverage Output (Continued); Unusual Brewer Noises Diagnosis

Page 13
SERVICE (cont.)
BREW SELECTOR SWITCH (cont.)
P1388
FIG. 4 BREW SELECTOR SWITCH TERMINALS
EARLY MODEL SELECTOR SWITCH
LATE MODEL SELECTOR SWITCH
Test Procedure (Late model Selector Switch):
1. Disconnect the brewer from the power supply.
2. Disconnect all wires from the brew selector
switch.
3. Check for continuity across terminals (b) and (1)
when the switch is in the small batch position.
Continuity must not be present in any other switch
position.
4. Check for continuity across terminals (b) and (2)
when the switch is in the medium batch position.
Continuity must not be present in any other posi-
tion.
TAN to Interface Socket
PNKtoInterfaceSocket
GRY to Interface Socket
WHI/RED to Dispense Valve
WHI/VIO to By-Pass Valve
To Timer
TAN
PNK
GRY
WHI/VIO to
By-Pass Valve
WHI/RED to
Dispense Valve
TAN to Grinder Interface
GRY to Grinder Interface
ORN to Timer
BLU to Timer
YEL to Timer
PNKtoGrinderInterface
b
d
4
3
2
1
e
5
5. Check for continuity across terminals (e) and (5).
When the selector switch is in the small batch
position, continuity should not be present. When
the selector switch is in the medium or large batch
positions, continuity should be present.
If continuity is present as described the switch is
operating properly.
If continuity is not present as described replace switch
assembly.
Removal and Replacement:
1. Disconnect all wires from the brew selector
switch.
2. Loosen the set screw on the switch knob.
3. Remove the 9/16" nut and washer holding the
switch to the hood.
4. Remove the switch.
5. Install the new switch. The positioning tab must
be in the hole in the hood for proper switch and
knob alignment.
6. Install the knob so that the arrow lines up in the
large batch position when the switch is turned to
the full right position.
7. Refer to Fig. 4 when reconnecting the wires.
41976 031709