How do you move the seat in a 93 mark VIII if the switches dont work?
I would suggest perhaps removing the seat and inspecting the wiring and plugs that operate the seat. Maybe a wire has come off or worn through over time from constant seat movement (like when you flip the seat back to get into rear seat)perhaps a plug has come off or has a loose connection. If that doesn't seem to do it go on E-bay (or an auto wrecker) and try and get yourself a cheap replacement seat switch. As with everything....time and patience...and a lot of swearing in the meantime!
What can you do if the gear shift button will not engage and the gear shift is stuck in park so you can't move your 1993 mark viii?
Optical switches are a technology that operates on fiber optic lines to work similar to traditional electrical switches. There are two kinds of optical switches: slow switches which are operated by mechanical means which physically move an optical fiber. These are used as long-term routing solutions if there is a fault in the line. Fast switches are operated using magnetic technology to do logic operations (computations) on the optical lines.