This is really useful - I'm trying to fix the same problem.
Which of the contacts should I be testing the resistance across?
There are 2 brown (power?) wires that enter two relay/switch like devices. These exit the relay/switches as black wires, which lead to the two pencil-like connections to the heater element.
I get infinite resistance between both the brown input wires, and also infinite across the two pencil-like connections.
I assume one of these is the correct test, is it??
Cheers, this has been really useful.
Paul G
Paul Greenhalgh, April 2007