How do I fill in the missing information on a Mazda RX-7 FD wiring diagram?

Difficulty: Moderate

To fill in missing wiring diagram information or figure out where an unidentified wire belongs on your FD RX-7, you should consult the Factory Service Manual (FSM) and trace the circuit logically.

Here is the procedure for identifying and placing stray or missing wires:

1. Verify the Wire Color: Do not assume an unknown wire is a ground. Many circuits will test as a ground when the vehicle is powered off but become a live circuit when turned on ¹. Determine the exact solid color and stripe color.
2. Locate the Bundle and Connector: Trace the wire back to its specific bundle to figure out which of the four main connectors it belongs to ¹.
3. Cross-Reference the Pinout Chart: Look for empty holes (pinouts) on the connector and compare them to the factory diagram. The factory chart is oriented as if you are looking into the back of the plug. Verify the colors of the adjacent, intact wires in the connector to ensure you are looking at the diagram from the correct direction ¹.

If you are working from an incomplete diagram, PDF copies of the full Factory Service Manuals contain the official wiring schematics ⁴. You can access and download the 3rd-generation FSMs here: ⁵

What year is your RX-7? There are differences in wiring colors and component configurations between the 1993 and 1994/1995 models, which will dictate exactly which factory wiring diagram you need to use ⁴.