Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect the ignition lead from the spark
generator and from the ignition electrodes
(The spark generator will slide up and out to allow more space.)
Disconnect the upper earth wire from the spark generator

Measurement:

Test 1:
Measure the resistance between each end of the earth wire on the ignition lead.
Test 2:
Measure the resistance between the ends of the red wire on the ignition lead.
Short circuit (zero Ohms) expected on both tests.
Note:
The connections to the spark generator may
differ in appearance but the test remains the same.