
While the Hybrid Racing Conversion Wiring Harness is 99% plug-n-play, there are a few wires that need
to be connected after the harness has been installed into the car. Because it involves electricity, there is
always the risk of damaging electronic devices, such as fuse boxes, ECU’s and sensors among other
things. Hybrid Racing strongly urges the installer of this product to become familiar with wiring and com-
mon wiring procedures before attempting to install this product.
If you are unsure of something, or have any questions regarding this product or its installation please
feel free to create a support ticket at support.hybrid-racing.com or email us at support@hybrid-
racing.com. Remember its easier and cheaper to email us than it is to damage something and have to
replace it.
This wiring harness is designed to integrate a K-series engine into the chassis specified on the first page
of the install guide, it serves no other function. It allows the engine, ECU and the chassis to communi-
cate together. Without it, the car will not function.
Each engine wiring harness requires the use of a charging harness. You must have a charge harness
installed or your car will not crank and run properly. This charge harness connects the alternator and
starter directly to the battery and fuse box. **All charging harnesses are NOT the same**. To avoid
using the wrong charge harness use the charge harness from the same chassis that your motor and
engine harness came from.
I. Engine Harness Selection
Below is a list of engine harnesses that are COMPATIABLE with the HR conversion
harness:
K20A (JDM 01-05 DC5 Type R)
This engine wiring harness is made for RHD cars and is shorter than the LHD versions.
Depending on how it is routed, It may be necessary to extend the end of the harness so
that it reaches into the cabin. It also does NOT have an oil pressure switch connector.
K20A2 ( USDM 02-04 DC5 Type S)
This is the most commonly used engine wiring harness. It is the best length and works with
both a 5spd and 6spd transmissions.
K20A3 (USDM 02-05 EP3 & 02-04 DC5 Base *5spd only)
This engine wiring harnesses is for 5spd transmissions and will NOT have the connector
for the reverse lock out solenoid on the transmission. This is not necessary but if you want to
have this function you will need a 6peed engine harness and ECU.
These engine harnesses ARE NOT compatible with this conversion harness:
K20Z1 (USDM 05-06 DC5 Type S)
This harness does NOT support the 05-06 RSX KPRO.
K20Z3 (USDM 06+ FG Civic Si)
Has Drive-By-Wire and different ECU connectors.
Any K24 harness
(any year, 5spd or auto)
If you have a harnesses that is not compatible, please obtain one of the compatible en-
gine harnesses before continuing with the installation. If you connect this conversion
harness to the wrong engine harness, you can damage the ECU, engine sensors and
any wiring *This is VERY important* if you are unsure email us at support@hybrid
-racing.com with a picture of your parts and we will help you figure it out.
Introduction & Installation Notes
A little bit of K-series information to make sure you have the right parts before you get started!