air con light,and air con dead?

got a scenic dci 19 2004 modeland had to have fan motor housing opened up a while back to remove debris(it was making a noisy racket on full speed ) ever since ,my aircon as not worked.dont know if they left a wire of somewhere,or neglected to re-connect a plug... ive had a little look around under dash when i had glove box out and steering column out but dont know where to start..checked all the fuses etc as well. anyone got any idea and locations to look ..garage that did the fan repair doesnt want to know and say it cant have been working.it was they were fixing the problem under warrantee