iWire Merge - Commonly Confused Plugs | iWire Subaru Wiring Solutions

December 2024 Update: iWire is no longer offering harness merge services so we can focus on other parts of the business, including iDCCD, plug-and-play harnesses, and replacement electrical components. As part of this change, our technical support, wiring guidance, and troubleshooting assistance for harness merge projects will be very limited moving forward.

We appreciate everyone who trusted us with their swap wiring over the years.

These blog posts will remain available as a resource for the Subaru swap community.

To learn more about why we ended our harness merge services, please read the blog post below:

https://iwireusa.com/blogs/iwire-university/why-are-we-ending-our-harness-merge-services

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In this blog post we talk about the plugs that are most commonly mixed up or confusing for our merge customers. Below we have pictures of each with a short description to help clarify things. This is specifically for 98-01 Impreza models. Many other models have similar connectors so this guide should still be helpful. Each picture has the description of what it is underneath it.

iWire DCCD Expansion Connector - This connector is included with all swaps for future DCCD expansion. If the transmission is changed to a DCCD model please call us and we'll set you up with a plug and play DCCD controller that will tie into that expansion. This plug will stay open and can be tucked away until expansion. If you go with a DCCD equipped transmission in the future please reach out since we'll get you custom kit that will plug into your merged harness.

If your Airbags are not working but everything seems to be plugged in double check the main connector is fully seated.

Brake Light Connector - Many harnesses are equipped with cruise and non cruise options. This 2 pin Brake light connector will be for non cruise models. If the pedal box is a non cruise model it will only have a slot for this 2 pin version of the connector which means the 4 pin model will stay open.

Hazard Connector - Commonly mixed up with the plug going to the steering column. Ensure the Hazard button is with the same harness as the Green connections going to the gauge cluster.

Steering Column Connector - This ties into the wiper stalk. Be sure this is not mixed up with the Hazard button on the Gauge Cluster sub harness.

Clutch switch for starter interrupt - This tends to be mixed up with the plug below for the windows. You can identify the clutch switch because the wire gauge is much smaller. The usual color combination is Green with Yellow stripe and straight Black.

Power Window Circuit Breaker - Feeds power to the windows and sunroof. This plug can be identified by the large gauge wire and the common colors of White with Green stripe and Black with White stripe.

Cruise Control Module connector - This many times will stay open, especially for non cruise equipped vehicles. For drive by wire engine swaps, you will remove the cruise module and leave this disconnected.

Data Link Connector - This is an additional port for the Subaru Select Monitor diagnostic computer. It will stay open and unplugged.

Diagnosis Connector - This connector can be used to diagnose sub systems on the car like cruise, airbags, or ABS. The 2 Black terminals are inserted in the front of the housing in specific locations to flash the corresponding light on the cluster to the system being tested. Codes are read OBD1 style with flashes that are short and long that correspond to a code for that system.

Keyless Entry Connector - Either this will tie into the keyless entry unit or if there is no keyless entry there should be a jumper on the two outside bottom wires. If neither exists, a jumper needs to be added to get the door locks working.

Rear Accessory Connector for wagon models - This will stay open for coupe and sedan models and for wagons it'll tie into a cylindrical type relay.

Test Mode Connectors - These will stay open other than for flashing. More on the test mode connectors can be found here.

Initialization Connectors - One or the other of these connectors (not both) will be found on 16 bit ECU models. There is a jumper that is supplied with your tuning software of choice for when the ECU is being flashed.