Selector Switch Testing; Bake Igniter Testing - Viking VGSO166 Service Manual

Service Diagnostics and Procedures

Selector Switch Testing

The selector switch controls the cooking operation.
When the end user selects a cooking operation, the
corresponding contacts within the selector switch
closes, supplying L1 power to the bake igniter, broil
igniter, or the convection fan motor. Switch contacts
BA to 2, BR to 1, and CV to 3 closes for bake, broil,
and convection functions respectfully.
To access the selector switch, open oven door
and remove screws securing control panel. Slide
unit out 6 – 8" and remove screw from right side
trim securing control panel. Remove nut securing
oven light switch, selector switch knob, and timer
buttons. Remove control cover and disconnect
wiring. Separate the control cover by removing
securing screws. The selector switch is now
accessible.
The selector switch receives L1 from the thermostat
timer AT3 (convection selected) or AT4 (bake or
broil selected). With bake selected, closed contacts
BA to 2 supplies L1 power to the left hand and
right hand bake igniters. With broil selected, closed
contacts BR to 1 supplies L1 power to the broil
igniter. With convection selected, closed contacts
CV to 3 supplies L1 power to convection fan motor.
Selector Switch
© 2009 Viking Preferred Service

Bake Igniter Testing

The bake igniter provides an ignition source for the
gas being supplied by the gas valve. Once the end
user selects bake, power is supplied to the bake
igniter and it begins to glow red.
Bake Burner Igniter
To access the bake igniter, remove the screws
securing the lower panel. With the panel removed,
remove the screws and brackets securing the bake
burner. Disconnect wiring and remove the bake
burner. The igniter is now accessible.
With a Volt-Ohm meter set for resistance, measure
the igniter resistance. The left side bake igniter
should be approximately 91 Ω and the right side
igniter should be approximately 135 Ω. Supply
voltage to the igniter is 120 VAC. As power is
applied the igniter begins to glow. A glowing
igniter does not mean it is good. Often times the
igniter will glow, however it is weak and does not
supply enough current flow to open the gas valve.
®
24