Certain Honda engine swaps require changes to the alternator connector.
In most cases, wire color matching does the job of figuring this out, but sometimes the wire colors are completely different. Â
OBD0 and OBD1 B/D-series engines and wiring use the same 4-wire round alternator plug, so they are compatible with each other ie. plug n’ play.
OBD2 B/D-series alternators on the other hand use a 4-wire Â rounded square plug and are compatible with OBD2 vehicles but are not backwards compatible to OBD0/1 wiring.Â
So, when using an OBD2 alternator (for whatever reasons) in an OBD0/1 vehicle, adaptation of the OBD2 alternator plug needs to be made to the OBD0/1 engine wire harness.
Here are common scenerios when trying to adapt older or newer alternators due to differences in OBD types :
OBD-1 to OBD-0 alternator connector
This scenerio happens when using an OBD1 engine in an OBD0 vehicle or vice versa.
As mentioned already, OBD0 and OBD1 alternators share the same round style alternator plug. Â Making this type of scenerio PnP or plug n’ play. No need to change the alternator plug here. However, for some reason the plugs differ, simply color match the Â wires and adapt the OBD-1 alt plug to the OBD-0 wire harness.
JDM OBD0 and OBD1 alternators use the same round style plug but only use 3-wires. Don’t let the missing 4th wire fool you. You can still use the JDM alternator with your 4-wire alt. plug.
OBD-2 to OBD-0 alternator connector
This scenerio happens when using an OBD2 engine in an OBD-0 vehicle.
When adapting an OBD2 alternator to an OBD-0 engine harness follow this wire color chart:
|OBD0 (DPFi – STD/DX)Â||Â Â — Â||OBD2 plug|
|Â yellow||Â toÂ||white/redÂ|
|Â black/yellow||Â toÂ||black/yellowÂ|
|OBD0 (MPFi – HF/Si)Â||Â Â —Â Â||OBD2 plug|
|Â white/yellow||Â toÂ||white/redÂ|
OBD-1 to OBD2 / OBD2 to OBD-1 alternator
This scenerio happens when using an OBD1 engine in an OBD2 vehicle and vice versa.
When adapting an OBD2 alternator plug to OBD1 engine harness and vice versa follow this chart:
|OBD1Â||Â Â —Â Â||OBD2 plug|
|Â white/yellow||Â toÂ||white/greenÂ|