after finding a broken windscreen wiper stalk on my 89 v12 convertible I swapped it for a replacement. now , the wipers when switched on will not turn back off without turning the ignition off and starting again? does anyone have any possible suggestions as to what this might be? thanks in advance

 

I bought a job lot of used switches which I had to test before selling them. What you have is one of the faults I found on a lot of them. I think providing its connected correctly
You will need another switch, if its the ford type there are a lot of alternatives