Vacuum Diaphragm Electric Switch & Throttle Body Switch

What function do these 2 switches perform. They are fitted on my 1986 Cab 1.8i. It's all standard. There are no mods, as far as I can tell. There's no engine code/serial number on the block, for me to quote to you. It's a UK model so, I suppose it's a DX engine.
Looking at the circuit diagram(s) in the Haynes manual, I can't work out what they do.

Got any ideas?