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Wiring Specialties RB25DET Pre-Made Swap Harness Nissan 240sx S13

5 Star Rating

Buy in bulk and save


If you’re looking to save some serious time and cash by replacing both your engine and transmission harnesses, look no further. This plug-and-play is for the RB25DET installed in a S13 240SX and requires no additional wiring. The handy premade RB25 S13 swap combo makes replacing both harnesses fast, easy, and affordable.


Please make sure your engine fits the following criteria before placing your order:

R33/Stage A RB25DET engine

  • Any RB25DET from 1994-1997 Skyline GTS-T
  • Any RB25DET from Nissan Stage A
  • Supports Series 1 and Series 2 engines
  • Only supports engines running a manual transmission

Chassis: S13 240SX

  • Any S13 240SX manufactured in 1989-1994 (Including the Convertible and ABS cars)
  • Transmission harness supports 5-speed and auto to 5-speed conversions

Product Features:

This outstanding RB25 S13 swap improves engine performance through better grounding and power wiring. It features brand new wiring and connectors, and each engine harness contains S1 and S2 MAFS connectors. It replaces the entire OEM engine harness, and it’s designed for a factory-like fit and finish for the S13 240SX. This unit retains OEM wiper functionality, as well as cruise control and other gauge functions.

- Works with the Greddy/Freddy intake manifolds
- All A/C, Temp override, Auto On/Off functions properly
- OEM wiring connections and 'T' junctions. No soldered connections at all
- Fully tested after production for an easy plug-and-play replacement
- Requires RB25DET/S13 Speed Sensors
- Transmission Harness supports 5-speed and Auto to 5-speed conversions
- Will improve engine performance through better grounding and power wiring
- Turn Key ENGINE START Guarantee

If you’d like more information about this RB25 S13 swap, please feel free to give us a call at 1-888-SR20DET.

We HIGHLY Recommend purchasing new injector and coil pack sub harnesses, most OEM sub-harnesses are worn from use over years and sometimes will not work properly, dont waste valuable time trying to diagnose and fix wiring problems from your old factory harnesses.


  1. Highly Recommended

    Posted by Unknown on

    I was doing the wiring swap on my own but couldn't get the car to idle. So i decided to buy this harness it installed extremely fast you couldn't screw it up. Just about everything worked properly but my tach is off just because a KA tach can't read a Coil on plug signal properly. I would recommend this to anyone.

  2. life saver

    Posted by Justin Meshell on

    the harness was a complet life saver as well as time. i had thought about just combinding my s13 harness with the with the rb25det harness. but i feared that i would fry my ecu. so i found the wiring specialties harness. just plug and play! i got it all hooked up put a little gas in the tank primed the gas system and shure enough it fired right up and held at 1,000 rpm. reverce lites, fule pump, mph tach everything worked GREAT there was no wireing problom at all!!! SO THANKS GUYS!!!! i will be puting the word out there that WIRING SPECIALTIIES IS THE WAY TO GO!

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