Wiring the Manual harness into an Auto body

Nissan 300ZX technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
bgibb
Posts: 15
Joined: Wed Oct 21, 2020 1:50 pm
Car: '90 Nissan 300ZX NA w/ '95 engine & '93 trans

Post

TL;DR Manual harness needs rewired to relay box harness of an auto body, and I need a guiding hand if you have any links/info/walkthroughs.
This is not a topic on the reverse light switch, no issues there. This is relay box harness specific (opposite side of engine bay).
INFO: Car has been swapped from an auto to manual. NA, LHD, new spec engine goodies.

STORY: Recently dropped the engine/trans/subframe unit (as nissan intended) and went through a ton of the external stuffs, including a new harness. As most of you know, they only produce manual harnesses anymore, which wouldn't be an issue, except for my car originally being an auto- the relay box harness does not fit up to the engine harness without some serious rewiring going on. I'm having a horrible time finding anything on this in previous forums, and an even worse time finding pinout/wiring info corresponding to this in the FSM. Anyone have any directions?


itsa300zx
Posts: 1287
Joined: Sun May 31, 2009 9:39 am
Car: 1990 300zx NA W/TT swap
2011 Nissan Rogue S
2008 Highlander SR5
Location: up North

Post

Sorry it does not answer your issues, but...

Wiring specialties makes a trans harness for Auto to manual conversions. Plug and play.

https://www.wiringspecialties.com/30altotrha.html

bgibb
Posts: 15
Joined: Wed Oct 21, 2020 1:50 pm
Car: '90 Nissan 300ZX NA w/ '95 engine & '93 trans

Post

Already snagged that one (albeit from Z1), but thank you anyway haha I was hoping there was some conversion harness between the two parts I'm looking at, but alas

bgibb
Posts: 15
Joined: Wed Oct 21, 2020 1:50 pm
Car: '90 Nissan 300ZX NA w/ '95 engine & '93 trans

Post

Ok so things worked out really well.

Turns out, the majority of the wiring from the 3rd plug was only for auto controllers, and had two wires that went to other locations in the other plugs. They color matched and everything, so all I had to do was repin/splice the Purple/dot and White/dot wires. Very simple, almost got it to look factory setup. I'll get you guys some pictures sometime, and I'll also be submitting the write up to Z1.

NOTE: I did have to get a computer from a manual Z (number 24, a gen1 manual ecu) in order to make sure the pinout from the harness matched the ecu pinout. However, car runs frickin great now.

mike.manziuk7
Posts: 1
Joined: Wed Dec 07, 2022 11:01 pm
Car: 1990 Nissan 300ZX JDM TT 2+2

Post

Hey, I’m trying to the same thing on my 90 z32 JDM tt auto. I have a manual harness that I’m trying to hook up to the stock auto TT ecu.

How do I do this exactly, because there is that 3rd connector by the fuse box?

Thx

neeyuhzx
Posts: 2
Joined: Sun Apr 27, 2025 2:43 pm
Car: 1990 Nissan 300ZX

Post

hey i’m going through the same issue and was wondering how you set up the spliced wires that were mentioned

User avatar
AZhitman
Administrator
Posts: 54538
Joined: Mon Apr 29, 2002 2:04 am
Car: 58 L210, 63 Bluebird RHD, 64 NL320, 65 SPL310, 66 411 RHD, 67 WRL411, 68 510 SR20, 75 280Z RB25, 77 620 SR20, 79 B310, 90 Z32, 91 GTi-R, 92 Silvia Qs, 98 S14, 23 Z.
Location: Surprise, Arizona
Contact:

Post

Hoping bgibb sees this and replies, but it's been 5 years. If you don't get a reply soon, let us know - I'll pull his email so you can send a message (or just PM him here)!


Return to “300ZX (Z32) Technical”