Rywire Mil-Spec Tucked D/B-Series Engine Harness, OBD1 - B-Swap for Civic, CRX, Integra (B1-Milspec)

Rywire B1-Milspec is a mil-spec tucked engine harness for D-series and B-series swaps, cross-compatible with both engine families. It is built from Tefzel (ETFE) Teflon-insulated wire rated to 200°C, covered in Raychem DR-25 heat shrink with adhesive-lined junctions to keep moisture out. This OBD1 listing defaults to OBD1 injector, distributor and alternator plugs, and you can also order it with OBD2 plugs and either distributor style.

Why This Mil-Spec OBD1 B-Series Swap Harness

The Rywire B1-Milspec is a mil-spec tucked B-series swap harness for D-series and B-series engines, built from Tefzel wire under Raychem DR-25 heat shrink, with OBD1 computer plugs and a chassis adapter.

• Versus re-pinning your donor or factory harness: donor harnesses are often 20+ years old, cut or missing plugs; this Rywire mil-spec harness is all-new wire, pins and plugs, pneumatically crimped, labeled and pin-to-pin tested.
• Versus a used junkyard harness: this Rywire mil-spec harness needs no core and comes with a chassis adapter built for the vehicle picked at checkout.
• Versus a universal flying-lead harness: this Rywire mil-spec harness arrives terminated for every D/B-series sensor, injector, distributor and OBD1 computer plug, with the injector plug you choose.
• Versus Rywire's budget line: this mil-spec harness adds Tefzel (ETFE) wire rated to 200 C, adhesive-lined junctions and an optional firewall quick disconnect, so the engine comes out without unpinning anything.
• Either engine-plug era: this Rywire harness defaults to OBD1 injector, distributor and alternator plugs and can be built with OBD2 plugs and a 10-pin or 8-pin distributor.

Best for: D/B-series swaps on an OBD1 computer where the harness faces heat, track use or repeated engine pulls. For a lower-cost tucked bay, pick B1-Base.

Engine Swap Fitment

• Honda D-series and B-series engines with OBD1 or OBD2 engine plugs
• Chassis adapters for 1984-2000 Civic, 1984-1991 CRX, 1990-2001 Integra and 1987-1991 Prelude
• Any other chassis, sand rail, buggy or drag car through the Rywire Race Fuse/Relay Box V3, which is also plug and play with the Rywire Switch Panel
• Engine computer: OBD1 plugs A, B and D. Aftermarket computers with OBD2 plugs and non-US OBD2 computers work through a computer adapter; USDM OBD2 computers and stock H22 and GSR computers are not supported

Features

• Mil-spec Tefzel (ETFE) wire, rated to 200°C, with high chemical resistance
• Raychem DR-25 heat shrink and adhesive-lined wire junctions
• Tucked routing; can take a firewall-mounted mil-spec quick disconnect so the engine comes out without unpinning anything
• All new connectors, pneumatically crimped and labeled for install
• Interior side is a separate chassis adapter, so a chassis change only needs a new adapter
• Pin-to-pin and resistance tested before shipping
• Built to order by Rywire in the USA

Connector List

• OBD1 engine computer plugs A, B and D
• Power distribution cap
• Injectors 1-4
• Distributor plugs (OBD1 by default)
• Alternator
• Throttle position (TPS)
• MAP sensor
• Intake air temperature (intake manifold style)
• Engine coolant temperature
• Coolant temperature sender for the gauge cluster
• Primary 4-wire oxygen sensor
• Knock sensor
• Oil pressure sending unit
• VTEC solenoid
• Idle control motor
• Electronic speed sensor
• Fan switch
• Reverse lights
• Starter signal
• Ground
• 2 extra wires

Choosing Options

• Chassis Adapter: your car, the Race Fuse/Relay Box V3 (with or without Switch Panel), Rywire PDM System, or Other / Custom / Race-Style.
• Engine Plugs: OBD1 if your engine has 1992-1995 injectors, distributor and alternator; OBD2 with a 10-pin or 8-pin distributor plug if it has 1996-2000 parts. Count the wire positions on your distributor plug if unsure.
• Injector Plug: the plug fitted at each injector. Bosch EV1 / Honda OBD1 is the stock choice; pick another if you run aftermarket injectors.
• Mil-spec quick disconnect plug: Rywire can add a firewall separation plug (mounted in the A/C hole by default) for an extra charge. Ask us for a quote.

Recommended Add-Ons

• Rywire Mil-Spec Firewall Quick Disconnect Plug - Harness Build Option.
• Rywire RyTi Titanium VTEC Solenoid Bolt - VTEC Oil Pressure Switch Delete.
• Rywire One-Piece Charge Harness - Honda B/D/F/H/K-Series Swap Harnesses.
• Rywire Engine Ground Kit - 4-Gauge Battery Cable & 8-Gauge Grounds for Swap Harnesses.
• Rywire Mil-Spec Connector Plate, 3 x 5 in - A/C Firewall Hole Harness Pass-Through.
• Rywire Mil-Spec Connector Plate, 3 x 3 in - A/C Firewall Hole Harness Pass-Through.

Add any of these from the Recommended Add-Ons list above. Each one is its own listing.

What's Included

• Rywire OBD1 mil-spec tucked D/B-series engine harness
• Chassis adapter or interior side as selected

Frequently Asked Questions

Can I order this OBD1 harness with OBD2 plugs?

Yes. Under Engine Plugs pick OBD2 with a 10-pin or 8-pin distributor plug. The computer end stays OBD1 either way.

Does the engine need to come out to remove the harness?

Not if you add the mil-spec quick disconnect. With the plug and a Rywire connector plate at the firewall, the engine side unplugs in one piece.

Which injector plug should I pick?

Bosch EV1 / Honda OBD1 for stock OBD1 injectors. Pick RDX, Nippon Denso/ID2000, EV14 or another style to match aftermarket injectors. Email service@tunedbyshawn.com with your engine, chassis and ECU before ordering if you are unsure which configuration you need.

Should I buy the budget or mil-spec Rywire B-series swap harness?

Both share nearly the same layout. The Rywire B1-Milspec uses Tefzel wire rated to 200 C under Raychem DR-25 heat shrink and can take a firewall quick disconnect; the B1-Base uses single-color black wire in expandable loom at a lower cost.

For off-road and competition use only. Not legal for use on pollution-controlled motor vehicles.