Rywire

The best engine harnesses and swap wiring for a Honda or Acura build are the ones made for your exact chassis, engine, and model years, and that is exactly what this Rywire range covers. It includes OEM replacement engine harnesses, chassis-specific adapters, K-Series chassis adapters, and power distribution kits for Civic, CRX, Del Sol, and Integra builds, so check your year and model before ordering.

An engine harness carries power and signals between the ECU, sensors, injectors, and ignition, so age, heat, and brittle connectors can cause hard-to-trace faults on older Hondas. A fresh harness restores those connections in one job. Adapters handle the other side of a swap: they bridge the engine harness to a different-generation body harness, which is why the adapter must match the chassis years and, on some listings, the trim, like the DX and STD versions for early Civic and CRX models.

When you shop, match three things: the chassis and year range, the engine family named in the title, such as B-Series or K-Series, and whether the listing is a full harness, an adapter, or a PDM kit. Left-hand-drive fitment is called out on some listings, so confirm that too. For supporting electronics, browse Ignition Systems and Engine Dressing alongside the wider Honda/Acura Performance Parts range.

Brands in This Collection

Rywire is a wiring specialist, and this collection is built entirely around its Honda harnesses and adapters. The range runs from the OEM Replacement Engine Harness for 92-95 Civic with B-Series and 94-01 Integra to chassis-specific adapters for 88-91 and 92-95 cars. That focus on one job, connecting Honda engines and chassis correctly, is what the brand is known for among swap builders.

For K-Series swaps, the K-Series Chassis Adapter Harness for 99-00 Civic is the bridge piece, and it pairs naturally with Hondata ECU tuning software. Hondata is the name Honda tuners reach for when a swapped engine needs a tunable ECU to run correctly, so harness and tuning are usually planned together rather than bought separately.

Builders finishing the engine bay often look at AEM electronics and gauges as well: AEM is widely used for engine management accessories and monitoring on swap builds. For more Honda build ideas, read Updating Your Honda: Make It Stand Out With Honda Performance Parts.

FAQ

Do I need an adapter harness for an engine swap?

Usually, yes. When the engine and chassis come from different generations, a chassis-specific adapter connects the engine harness to the body harness so the ECU, gauges, and accessories communicate correctly.

How do I choose between the adapter versions?

Match the chassis years and trim in the product title exactly, for example the DX/STD versions for 88-91 Civic and CRX. If your year and model are not listed, check your year and model against the title before ordering.

Is a replacement harness a difficult install?

It is a methodical job: the harness routes through the engine bay and firewall, so allow time, label connectors as you remove the old harness, and consider professional help if you are not comfortable with wiring.

Does a new harness require a tune?

A stock replacement harness on a stock engine does not change the tune. A swapped engine, such as a K-Series conversion, generally does need ECU tuning to run properly.