AC assistance

[deadscoob]

I'm having what appears to be a fairly erratic problem with the AC which is proving quite hard to resolve. Basically, it is no longer coming on.
The relay has been checked and appears to be working.
If I bridge the binary switch sometimes the fan comes on, sometimes it doesn't, but I can't trace a fault to the fan which works with direct power.

I "think" the temp control switch is faulty, it's been rebuilt once already.

Can someone smarter than me let me know the best steps to go through to prove the culprit?

I don't like the temp control switch, am pondering again if it's simpler to replace with just an on off switch.

Cheers

[deadscoob]

Yeah it makes sense to me. A small risk of it freezing, but can't see that ever happening?

[deadscoob]

I didn't mention it had been regarded.

Took the temp switch apart and it's that. POS