Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove the flame ignition harness from the spark generator

Measurement:

Test 1:
Measure the resistance the two spade connections on the ignitor
Expected resistance approx. 3.2 MOhms
Test 2:
Measure the resistance between the first spade and Earth
Expected resistance 1 MOhm or greater.
Test 3:
Measure the resistance between the second spade and Earth
Expected resistance 1 MOhm or greater.