How to remove wire terminals from the harnesses
Thankfully, Nissan has made it very easy for us to modify wiring harnesses throughout the car. The cluster harnesses you'll be rearranging the wires in, have an intricate plastic part that keeps the terminals from coming out of the harness. You'll need a small jeweler's screwdriver, an awl or some small picks. They work well for lots of things, especially in this application.
The first drawing shows one of the long sides of a cluster harness. You can see the tab that you depressed to release this side of the harness from the cluster, as well as the open areas where the metal terminals that the wires are connected to. Using a jewelers screwdriver or an awl with a dulled end, press into both areas marked as indentations on the drawing. The plastic should shift to the left, towards the terminals. If you pull up on the plastic just behind the release tab, you can pull this plastic up and out from behind the terminals. See the third picture, a side view of a harness with before and after renditions of this. Once you understand how this clip is released, it should make sense how to do so on the other side of the harness, as well as other harnesses for the cluster.
Now you don't have to worry about the wires falling out, they are still held in by individual plastic tabs inside the harness. To fully remove a wire from the harness, again, using a small jewelers screwdriver or an awl, depress the plastic tab while gently pulling on the wire from the opposite side of the harness. See the second picture. The tab is kind of far back in the hole, you kind of have to wedge between it and the terminal. Once you understand how this works for one wire it should make sense how to remove the rest of the wires.
I don't have harness numbers or terminal numbers for the '91-'92 cluster, so I've done my best to describe each harness. The letter/number after each wire description tells you what harness in the '93-'94 cluster you need to swap the wire to (M30, M32, M33, M102) and the number after the hyphen is the terminal number within that harness. See the harness and terminal diagram below. If your car is an automatic, has cruise, has an airbar or is Canadian Domestic Marketed, you may or may not have or need a spare indicator light location to install the airbag indicator light. The Odometer off indicator would be the best location to install an airbag indicator light if possible. The information is written to show how you'd swap a '91-'92 cluster into a '93-'94, although you should be able to work it backward just as easily to install a '93-'94 cluster into a '91-'92. Swapping of speedo sensors in the transmission will be required, drilling a hole in the firewall for a cable driven speedo, or running a pair of wires from the electronic sensor in the tranny to the cluster, will be required, all depending on which cluster you're swapping into which car. From what I can tell, M30, M32 and M33 harnesses in the 93-94 are the same three harnesses used in the 91-92. So in order to swap a 93-94 cluster into a 91-92, youd need to get ahold of the M102 harness since your car wont have it. In the opposite case, youll end up swapping all of M102s wires into the other harnesses and end up not using M102 at all.
Why would a person go to all this trouble to install the incorrect cluster in their car? Your guess is as good as mine. Probably the same reason a person would drill a hole in the firewall, and hack into their coil wiring to install an aftermarket tach, when ALL B13's have a tach wire at the ECU located right inside the car. So, this information is here so that it's available should someone decide to do things the hard way, which they often do. And I had a '91-'92 cluster with harnesses I got for free to play around with, so I thought I'd indulge my electrical fetish some more since I'd already written the previous cluster swap article.
91-92 cluster wiring
Right side 12 slot symmetrical plug black
Orange/black CEL M30-35
Green fuel M102-1
Red/white door open M102-2
Blue/white washer (canada) M32-10
Red/black low fuel M102-5
Yellow power for fuel gauge, ABS light, seatbelt, brake, oil pressure, temp gauge, speedo, battery. M32-15
Blue clock backlight M30-38
Blue/red ABS ground M102-7
Green/black left turn signal power M102-8
Black ground M33-27
Empty slot to the left of Green/black M33-25
Middle 10 slot, offset plug black
Black (top left) Tach ground (add a ground or use one thats unused)
Black (bottom left) Ground for speedo only
Black (bottom right) Ground for high beam indicator M32-12
Black/red high beam indicator M32-11
Blue/black tach signal M30-39
Red/black - clock M30-37
Yellow/green speedo M102-6
Left 12 slot, symmetrical plug white
Yellow/black left seatbelt ground M32-14 (4-door) M32-9 (2-door)
Yellow/green left oil pressure ground M30-33
Purple bulb check M30-31
Yellow/green right temp signal M30-41
Yellow/black right brake M30-32
Black/white- overdrive off ground M33-19
Yellow/red battery ground M30-36
Green/Yellow right turn signal power M33-26
Red/blue illumination M33-21
Red/yellow illumination M30-40
Black temp ground M102-3
Two wire buzzer plug
Red/black
Green/white
M32-16 Green from speedo sensor
M32-18 Red from speedo sensor
'93-'94 Electronic speedometer cluster wiring info:
M30 Plugs in horizontally behind the temp gauge on the bottom left hand side of the cluster (when looking at the back)
M32 Plugs in horizontally behind the fuel gauge on the bottom right hand side of the cluster (when looking at the back)
M33 Plugs in horizontally behind the tach
M102 Plugs in vertically above M32
M102 - 7 wires
1 G/L Fuel gauge
2 R/W Door open indicator
3 B Ground for water temp, fuel, tach and speedometer gauges as well as airbag indicator and clock
5 R/B Fuel indicator
6 Y/G Speedometer gauge
7 L/R ABS indicator
8 G/B Left hand turn signal indicator
M32 - 9 wires
9 Y Seatbelt indicator
10 L/W Washer indicator (Canada only)
11 R/B High beam on indicator
12 B Ground for high beam on indicator
13 R/W Airbag indicator
14 Y/G(4door and NX)Y/B(2door) Seatbelt indicator
15 Y Power for Abs, fuel, brake, overdrive off(auto), door, malfunction, washer(Canada), charge, and oil indicator lights, water temp, fuel, tach, and speedo gauges.
16 G Speedometer gauge
18 R Speedometer gauge
M33 - 5 wires
19 B/Y Overdrive off indicator (auto only)
21 R/L Meter illumination
25 G/Y(2door)G/R(4door and NX) Cruise on indicator
26 G/Y Right hand turn signal indicator
27 B Ground for turn signal indicators
M30 - 10 wires
31 PU Brake indicator
32 Y/B Brake indicator
33 Y/G Oil indicator
35 OR/B Malfunction indicator
36 Y/R Charge indicator
37 R/B Clock
38 L Clock illumination
39 L/B Tachometer
40 R/Y Meter illumination
41Y/G Water temp gauge
