Any old Mercury carenthusiast know about a feature wherethe power windows and the blower do not work when the top is down

no.....no such feature to my knowledge.... l think you may have a short circuit in your car if this is happening.

What a great car to own, & very rare.

It does sound to me like there is possibly a short caused by the top being down. If the car was just restored or rewired maybe what is happening when the top is down u r pinching or grounding out a main harness against the body. l have actually done this myself, l ran a bolt into a main wire harness that grounded out against the body when the headlights were on. What l was told by an auto electrician, retrace ur steps of what u did. Maybe as the top comes down it pinches a wire harness against the bows of the top or the body. Look & follow ur wire harness to see if any of it has come loose or is not held down correctly. Look for pinched wires.

Another problem, did u rebuild or replace the engine. Have u installed the main ground wire from the manifold to the firewall. This is a common mistake & without that ground wire ur electrical system will reek havoc on ur electrical.

l hope that helps & l sent u a link to the Mercury Car club.