Hey guys,
This may have been asked before but I could not find it so I shall ask. I have a 1991 300zx N/A manual with a TT swap done to it (Previous owners handy work and its horrible) I now need to replace the wiring harness and got a harness off a TT automatic and was wondering if it will fit. Thank you in advance, Bogdan

 

You can download the FSM with the wiring diagram, the harness does not vary much between auto and manual and could be adapted using the wiring diagram and maybe parts of your old one to get the connectors correct for the neutral switch, clutch kill switch and probably a few others.

 

First Google-machine result:

http://www.z1motorsports.com/PDFs/NATTconversion.pdf

ELECTRICAL
1.
Nissan claimed the TT coil packs were different a
couple years ago and charged a lot more for
them. I checked them and found that they were the
same and now Nissan lists them as the same.
I guess they got caught on that one.
2.
Of course the ECU is different, along with a diff
erent transmission computer on the automatics,
other than that there are no control units that mus
t be changed. We can upgrade a NA ECU to
upgraded TT specs for $250 which is usually a bette
r idea than buying a TT ECU then paying to
have it upgraded later. We strongly suggest sticki
ng with and just upgrading your existing NA
ECU when performing a TT conversion. It properly c
ommunicates with your existing NA fuel
pump control module. If you have an existing TT EC
U that came with a front clip or a parts car
you are using for the conversion, we will give you
credit for the TT ECU against converting your
exiting NA one to an upgraded TT program.
3.
The main engine (EFI) harness is different also,
but a NA harness will work in an TT, you just
will not have the connections for the boost control
solenoids which you don’t need anyway if you
have a boost controller. I don’t recommend wasting
your time with the conversion if you are too
cheap to buy a boost controller. If necessary we h
ave an easy way to remove the engine harness
without removing hardly anything inside the car. T
here is an aluminum bracket bolted right inside
the firewall that makes the engine harness difficul
t to change. The bracket is bolted in behind the
heater core and AC evaporator so it is hard to remo
ve from the inside. We take a pneumatic
reciprocating saw and cut the passenger side of the
bracket into from inside the engine bay and
then with some prying the bracket pivots around on
one bolt and moves out of your way. If you
use an your existing NA harness or a new NA harness
do not use a TT ECU. Simply have Z1
upgrade your existing NA ECU and send you TT ECU in
for credit.
4.
If converting NA --> TT, I would leave the interio
r harness and gauge cluster alone. They will
work with the TT setup. Get a stand alone boost gau
ge because the stock one is inaccurate. You
would be insane to add the HICAS system or stock el
ectronic adjustable suspension to a NA so
you will not need the TT interior harness. I woul
d leave all major wiring harnesses alone when
doing a conversion.
5.
MAF, PTU, TPS, IAA, AIV, EGR, O2 sensors, Detonat
ion sensor, Coolant temperature sensor
are all the same.
6.
The electrical AC Condenser fan is different on a
TT. The motor has three wires (2 speed)
going to it as opposed to two (one speed) on the NA
. But you can get by with the NA one on a
conversion. The mechanical fan is the same but the
fan clutch is different. The TTs have a yellow
dot on the front and are tighter than the NAs with a
n orange dot.
7.
The starters are all the same.