Could it be as simple as a clogged hose. If these are not used very often, sediment fills up the low spots in the hoses. Well in the case of the light washer, as one side is working and it come form the same place.

Wayne

 

I agree with cjd777 on the headlamp washer: they're both fed from the same pump. Or possibly, the arm is stuck? I think they're extended by the water pressure.

Try to stay away from the dealer. He wants to sell you a new car, and I'm not sure that even the Jaguar diagnostics is quite that smart. Look for a good auto-electrician to troubleshoot the screen wash issue.

 

Thanks to all who replied,I'll keep looking for an auto - electrician but they seem to be a dying breed ,in danger of extinction