Radio Wiring and What I’ve learned (Updated 04/01/2019)
Since the head unit article was published, I’ve had a few questions about wiring a later model Nissan stock radio into the S13 without cutting the stock harness. For those that are familiar with car audio bare with me, some of us are getting our feet wet and a basic audio setup is as far as I’m ever going to go. Before I was able to do anything, I had to replace the stock harness/plugs because they were cut. If you own an S13 and find yourself in the same position, this is the harness that you need:
To wire a head unit without doing any cutting, you will need the following harness, it plugs directly into your factory harness (and the above harness) leaving you with wire extensions (just like you would have after cutting your harness) to wire directly to an aftermarket harness.
Connecting a later model Nissan/Infiniti head unit is the same as an aftermarket unit. Unlike an aftermarket unit, stock head units do not come with a wiring harness, so you can either cut the harness from the car you are taking the unit from or simply buy a new one. Let’s take a look at the head unit I just picked up.
Here’s a rear shot of it. For this to work, it has to be compatible with my system* and I will need a nissan OEM radio harness for a 1995 or higher.
NOTE* to my knowledge, all these units will not work with the factory speaker system and will require you to run new speaker wire.
To complete this setup, the 1995 harness plugs into the head unit and the loose wires are color connected to the loose wires from the adapter harness. Using the proper adapters ensures that your factory harness stays intact and your wiring clean.
Below you will find the wiring Key for 1989 + Nissan/Infiniti vehicles.
Wiring diagram for 1989+ Nissan/Infiniti OEM radios.