Why won’t the oven heat up

I've replaced two faulty parts in my oven after a small explosion stopped it heating up, but I still have a problem.

1. I replaced the fan element at the back.
2. I replaced the thermal cut-out attached to the upper element.

Both were obviously dead. The element had a huge hole in it and the cut-out had no conductivity.

Here's the current situation:

• The oven still won't heat up.
• The grill does work (always did).
• The temperature light comes ON, and never goes off.
• The cooling fan runs constantly, even when the oven is OFF.
• All heating elements show conductivity (26Ω-55Ω)

Worth mentioning that the thermostat seems to work, because the temperature light does turn off when using the grill to reach temperature.

Why does the cooling fan stay on and the elements stay cold?

What other parts can I check for faults?

Additional notes:

• I'm confident new parts are wired correctly and securely
• Mains input gives 233Ω between live/neutral when off. 111Ω when oven switched on.
• New new cut-out is marked 16A, whereas the old part was 10A. Supplier assures me it's compatible with my oven.

Update:

I may have bought the wrong fan element by matching it to the product number on the part itself. I've opened a separate question about this.

Update 2:

The selector switch is fried. Copper melted between two connectors. Will fix or replace and post back if still not heating.