On my '59, the defroster lever has always been a little stiff. I was slowly working it on & off when something "gave way". It now moves from on to off with little or no resistance, so I'm assuming it has either broken the cable or the cable has come adrift from the lever.
I'm not sure where to start checking as I don't know where the cable goes to from the lever.
My questions are:
What is the easiest way to check what the problem is??
Can I get to the problem area without removing the centre console etc??
What does the defrost cable attach to??