Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hello, this is most likely an issue with the climate control panel itself. The control head is run by vacuum. Over time the vacuum seals inside the panel can leak and cause the wrong vents to be selected. The option is to replace it with a new one which is very expensive, well over 600.00 or more. Or to see if there is a shop in your area that rebuilds the control head and disassemble it and replace the vacuum seals inside it.
Do you need more help with this concern?