Set Appliance State:
Set Multimeter to Resistance 
Isolate Mains Power to appliance as per TOPs P4
Measurement:
Disconnect the Spark Electrode Lead from the PCB.
Measure the resistance between the Spark Electrode and the Spark Electrode Lead spade terminal.
Also check for signs of damage.
Measure the resistance between the Spark Electrode and the Spark Electrode Lead spade terminal.
Also check for signs of damage.
Isolate as per TOPs P4
and refit as necessary