So I am guessing that you have a late air cooled car . What was the problem with the original switch 
Thanks for your help mate.
It's an '85 126 Brown, It failed the MOT on dodgy lights (indicators come on with sidelights, headlights flash etc.)
I thought this was a bad earth somewhere, but apparently not. After hours of searching through spaghetti, I got an auto electrician to check it out who traced it it to the steering column switch. He is 100% certain that the switch is knackered. I ordered a replacement from Axel Gerstl which turned out to have the wrong connectors (all 4 pin). Ordered another from Ricambio with the correct connectors (not an original 126 part, I think 127 maybe) but the wires were in a different order so everything lit up like a xmas tree! Apparently there are 3 or 4 different configurations of switch for a 126 for reasons unbeknown to me and I can't seem to get my hands on the one I require. I emailed FiatClassic in Germany and apparently they have the correct one, but I refuse to pay the €85.50!! (without postage) they are asking for it. I'm now looking down the x19 route as apparently they are the same switch. I just can't afford to keep buying switches and returning them when they wrong ones arrive. HELP!
Cheers
Si