peaugot 206 left hand back indicator light not working?

our peaugot 206 left hand back indicator light wont work ,we bought a new box and fitted it it but then the car wouldnt work ..it wouldnt start ,any help would be aprieciated as we are in spain but the car is an english right hand drive we got the part from the u.k. so it was for a right hand drive car..do we have to go through a lot of expence just for a back indicator light ??we cant use the car now as it needs its itv and it wont pass without the lights working.! thanks for any help...