My 1990 Stanza has the fuse listing inside the cover of the fuse box.
There is no OBD connection on a 1990 Nissan as that is an OBD1 vehicle not OBD2. However there is a way to read the codes. https://codes.rennacs.com/Petrol-Engine/Japanese-Korean/Nissan-Engines.php
The 2001 Nissan Maxima OBD 2 port is under driver side dash below steering column
The 2005 Nissan Quest OBD 2 port is under driver side dash above accelerator pedal
The 2005 Nissan Maxima OBD 2 port is under driver side dash below steering column
On a 1990 Ford Thunderbird : There should be an EEC TEST connection in the engine compartment for the OBD I , EEC IV system
The 1995 Ford Escort OBD connection is located on the right hand side of the engine. The OBD connection will be on the air intake manifold.
OBD 0
OBD 1
OBD connection is usually under the dashboard to the left of the steering column.
Should be OBD I, OBD II is 1996 and newer
The 2007 Nissan Maxima OBD 2 port is under driver side dash left of steering column
Left of the steering wheel on the dash, behind the access panel for the fuses.