What would cause a speedometer not to work on a 1994 Nissan Pathfiner?
Either the sending unit is bad or the speedometer in the
instrument cluster is bad. On a '94 the sending unit is plugged
into the transmission in 2 wheel drive & in the transfer case
in 4 wheel drive. It has a small gear in it which turns with a gear
on the main shaft of the transmission/transfer case. Both parts can
be tested with a multimeter for proper functioning. If they both
work, the problem is in the wiring or the connections.