I've bought some second hand switches that I'd like to use with some LED lights on my disco, I want to put them under the clock where the front fog light switch sits between two blanks. The switches I'm playing with were originally for the rear fog lamp and the heated rear window. I think I've worked out the wiring patterns (1 - feed, 2 - night illumination, 4 - earth, 5 - load) but when playing with my multimeter I cannot get the switches to latch on (I do get contact when the switch is pushed in but that's lost when the switch is released), however when I swap them with the relevant switch on the disco they work fine. Can anyone shed light on what I'm doing wrong please?

Thanks in advance.

That's correct, u have momentarily switches which only signal the MFU which actually does the switching.
You require either rear wiper, front fog, cruise control or a/c they are the only switches that are latching.

If u still wish to use your switches U will need momentarily relays to accept the brief signal from the switch.

Many thanks, I was wondering if I'd lost my touch ;-)

No you haven't lost your touch. The rear wiper switch is a different shape the top bends slightly to follow arround the dash edge, it will look odd if fitted in the lower row, u require the style of the other switches I mentioned with just the flat top to the button if you intend using them.

I have a spare cruise control switch I no longer have use for