From: Bora Akyol 
Date: Mon, 11 Dec 1995 04:39:27 -0800 (PST)
Subject:    Here is how to replace the power window motor!(long)

Hi  everyone

I finally replaced and thus fixed my power window motor in my 86 300ZX. 
Here is how I did it. Maybe we could put this on the web page for future
reference. As I hear this must be a common problem for 84-89 300ZX's.

Cut here----------------------------------------
How to Replace your power window motor?
Nissan 300ZX 84-89.
Bora A. Akyol

Copyright 1995, May distribute freely under the GNU Public License Agreement.
Note that this is provided as free advice, and the author is neither
liable nor responsible if something goes wrong. 

In this how-to I will try to explain how I replaced the power window
motor with a new one.

The symptoms that I was having were: 
1.  The power window motor would whine but not work.
2.  When assisted by hand the window would come up and go down.
3.  When assisted by hand the power window motor would keep on
going and going, and going although the window was all the way up or
all the way down. Normally it should stop once the window is up or

The tools you will need for this task:

1.  Magnetic head screw driver (Phillips medium size).
2.  Power Screw Driver
3.  Socket wrench and SAE sockets. I don't remember the size.
4.  3 screws. (M6x16 pan head ) You will need these screws to
    replace the ones that Nissan put on the motor assembly. The ones in my
    car were of extremely poor quality and also easy to strip. 
5.  Some elmor's glue.

How to:

Step 1: Start by unscrewing the cover for the door lock handle. It is
black and the screw is located right next to the door lock knob. Then
unscrew the red door light on the inside of the panel. Finally unscrew
the four screws that attach the door handle to the panel. All of these
screws are Phillips heads. When the door handle comes loose, detach
the power window switch cables. 

Step 2: At this point you should be able to remove the panel.Do this
very gently. Work your way from the bottom. There will be about 6
plastic tacks and you don't want to break them as they are hard to
find. Once the panel is loose from the bottom. And you can lift it up
about 10-20 degrees; lift up the panel slightly and rock it back and
forth while pushing up. This will allow you to take the panel off the

Step 3: Now you will be able to see the plastic wrapper that separates
the door metal from the panel. Before you attempt to take apart the
panel unscrew the four screws that hold the right front speaker
assembly in place. These will be on the exterior assembly cover which
will be silver colored. Once you remove the speaker assembly with the
speaker on it, detach the speaker wires. After the speaker assembly is
removed, gently remove the white plastic wrapper material from the

Step 4: Now we are awfully close to removing the window glass. Raise
your window all the way up. Then lower it so that the two screws that
attach the window glass to the power window assembly align with then
two holes on the door. These holes are at the same level and separated
by 40 cm. or about 15 inches. The one hole that is closer to the front
of the car is smaller, the other one is considerably larger. 
 Tape the window in place once these screws are aligned. I have found
that packing or shipping tape works pretty well. Once taped, take out
those two screws. The glass should come loose but stay in place
because of the tapes. 

Step 5: Unscrew the four bolts that sit on a rectangular pattern about
midway in the door. These will be bolt (hex) shaped but will also have
Phillips heads. Use the wrench and the socket to unscrew these four
At this time also unscrew the two bolts that are closer to the tail
end of the car. These will be at the same level as the other
four. These two hold the pivot point for the power window
assembly. Detach the power window motor wire. 

Step 6: At this point you are able to move the whole power window
assembly back and forth inside the door. Make sure that you make the
whole assembly the most compact size by moving the rollers all the way
towards the front of the car. Then move the whole window assembly deep
inside the door towards the speaker opening. Use a little bit of force
to rock the front end of the power window assembly loose from the door
and pull the whole thing out. This step is kind of hard; you have to
get the right angle to pull this thing out. It is very tight but it
does come out.

Step 7: Grease, or replace the old motor. Make sure you mark the way
the spring assembly is inserted before you detach the power window. 

Step 8: Put everything back together in the reverse order. Also use
the new screws you bought to replace the screws that attach the power
window motor to the assembly. Use the magnetic head to attach the window 
glass back to the assembly.

Good Luck.