Thanks for the replies,
I remember accidentally slamming part of the cable in the garage door of the van so thought that it could be the cable. However, I tested it by connecting it to the current house sky cable using a coupling joint and then connecting the suspect cable to the box, hey presto signal was full!! This got me worried that it was the dish
However, I tried the sat finder on the house dish again and it was giving nothing and this dish is perfectly alligned. So I tried to allign the multimo without the sat finder. I knew the general direction so just turned it bit by bit very slowly, then all of a sudden the tv showed full signal and quality
This proved it wasn't the dish so must be the sat finder. So im off tomorrow to get a new sat finder from Maplins.
Thanks again for all the advice.