Why do i keep blowing.. giggedy.. switches

[Niall]

Think you need to do some investigating before you go replacing the switch. Try taking the bulbs out the holders and see if there is any corrosion. If so, get some lighter fluid and clean it all off then try again

Shall do ; i'll get a voltmeter on them when eli's home in case both bulbs have gone at the same time

I'll give the plugs and bulb connections a good clean scrape up

Cool easiest thing is to get a volt meter on the supply wire from the switch as far back as possible and see if you are getting 12v. If you are, you know the issue is with the plugs onto the board, the boards them selves or just bad luck and you have blown two bulbs at the same time!
Id also check earths although that wouldnt cause you to need 3 different switches