four ways

Bad earth under the washer bottle?  Duff connections in the gubbins that make up the actual switch inside the steering column?  Funky relay? 

Check the earth's first,  then the relay.  I keep a spare one just in case.  You can find them on eBay. In my experience,  most old LTs suffer from the rot in each bottom corner of the windscreen.  So essentially you get a nice rotted hole right above your fuse box on the left and right above a cluster of earth's behind the washer bottle on the right.  Most of the time you won't know you've got the rot until you have the screen out but a good indicator is the condition of the drivers floor pan.  Perhaps the earth's are a bit corroded.  The fuse box is partially protected from drips by an additional metal plate welded above it and below the problem area on the bottom left of the screen so that doesn't tend to get wet. I've had a few relays go bad though.  I bet it's one of the two. 

whats the score with replacing the switch mate ? Steering wheel off etc     spesh 

ha ha nice one TT just priced one up on fleabay , you were spot on price £40    thanks again