Rywire B/D Series Tucked Engine Harness for 90-91 Integra

Rywire B/D Series Tucked Engine Harness for 90-91 Integra

The engine harness in a 1990-1991 Integra is 35 years old now, and if the car has had a B-series swap at some point, somebody has already been in there with a test light and a roll of electrical tape. This is the way out: a new Rywire tucked engine harness built for OBD2 engine components, with the chassis adapter for the early DA's interior and shock tower plugs included in the box. New loom, new connectors, and the OBD0 chassis handled at the plug instead of with splices.

Part number RY-B2-DA-EARLY is the OBD2 version. The engine side gets OBD2 distributor, injector, and alternator plugs, and the ECU side is OBD1, connectors A, B, and D. That combination is the point: a 96-01 donor engine keeps its own electricals, and you tune it the way these cars actually get tuned, on a chipped OBD1 ECU or an S300.

What It Is and Why It Works

Rywire builds this B-series engine harness (D-series compatible) to the same design as their Mil-Spec line and saves the money on presentation, not construction: single-color black wire in expandable loom instead of the pretty stuff. Every connector and material is new, each one crimped with pneumatic heads for an OEM-grade crimp, and every branch wears a white ID label so the install makes sense while you're doing it. The finished harness is pin-to-pin tested and resistance checked before it ships, and it's made in the USA.

The design detail we'd point at first is the back side. The section that runs to your interior and shock towers is a separate chassis-specific sub-harness, and on this part number it's the 90-91 Integra USDM adapter. It unplugs from the main loom, so if you ever sell the shell and keep the drivetrain, the engine harness follows the motor and you only buy the sub-harness for the next chassis.

ECU support has one hard edge. OBD1 computers are the design target. An adapter can connect aftermarket OBD2-plug computers and non-US OBD2 computers, but stock USDM OBD2 ECUs are not supported, and Rywire excludes stock H22 and GSR computers as well. If the plan is a chipped P28 or an S300, you're exactly who this was built for.

Specs

Fitment

This part number is the early DA only. Honda changed the chassis-side connectors for 1992, so a 92-93 Integra takes the same engine harness with a different adapter, not this one. And because the engine plugs are OBD2, this version matches an engine wearing OBD2 injectors, alternator, and distributor, which usually means a 96-01 donor B16, B18, or B20, or a D-series converted to match. Rywire doesn't make an OBD2-to-OBD1 alternator adapter, so if your engine still runs OBD1 electricals, order the OBD1 version of this harness for the same chassis instead.

What to Know Before You Buy

Plan the whole circuit before the box shows up. Rywire's one-piece charge harness for starter and alternator power, injector plug adapters, a ground kit, and their titanium VTEC oil pressure bolt are all options they sell alongside this harness, and none of them come included here. If it were our build, the charge harness goes in the cart with it, because the stock charge wiring is as old as everything else you're replacing.

Two more things worth knowing before you order. Rywire warranties these and guarantees them to work, but once a Rywire harness is installed it can't be returned, so confirm your ECU, injector plugs, and distributor first. And if this is part of a fresh swap, run the harness while the motor is out of the car. A tuck with the engine in the bay can be done. Nobody enjoys it.