find the actuator
it will be on the side of the centre consol
traditionally (r32-c34) its on the drivers side level with the steering column
but being an m35 it could be elsewhere
unplug, clean and replug it, that may fix the problem
next step would be to remove it, disassemble it and re-solder the joints inside as they are prone to going dry and brittle in earlier nissans
failing that, get a second hand unit
failing that, a new unit