check your fusible link,its connected to your positive battery cable,it could be burnt or swollen and not making a good connection.
Starter lockout relay, next to the battery.
Right next to the cruise control turn on switch
Remove the positive battery cable from your 2001 Nissan battery. Remove the cables from the front of the starter. Remove the starter retaining bolts. Reverse the process to install the new starter.
For my 1994 Nissan pathfinder, which as im told is identical under the hood, the clutch interlock relay is on the sidewall by the battery. Grab a Chilton manual that covers that year, they have a good picture of it but mine is blue and the second closest relay to the battery itself.
The starter relay can be found underneath the hood on a 1991 Nissan pickup. The starter relay is beside the battery on the passenger side.
follow the positive battery cable to the starter.
Follow the positive battery cable ; it will lead you to the starter. Mark
Follow your positive wire from battery and it should take you to the starter that is hooked to the transmission.
Remove the positive cable from your 1995 Nissan Pathfinder battery. Remove the cables from the front of the starter. Remove the starter retaining bolts. Reverse the process to install the new starter.
If it won't turn over then suspect the starter. Check for power at the starter itself.
weak battery or bad alternator.
unbolt it from underneath. remone battery first