...RX-7 Stock Harness and Identifing Connectors & Wires Of Interest...
'89-'91 RX-7

Front Harness... this harness is the main harness for the front of the RX-7. It's basic job is to connect all the other sub harnesses in the front to the rest of the car. It comes thru the firewall on the extreme driver's side of the firewall, and runs forward to the radiator support to the relay rack (under the plastic cover in front of the radiator), and across to the horns, the coolant level sensor (in the top of the RX-7 radiator), headlites, front parking lites, etc. The front harness also connected to the engine harness at X-01, X-05, X-07, and X-08. It connects to the Emissions harness at X-11.
Engine Harness... this harness is located on the driver's side of the engine compartment. It contains wires to the rotary engine's battery cables, ignition system, starter, alternator (non-turbo), oil pressure sender, transmission switches, dash gauges, and various warning sensors. This harness is no longer needed, but it contains some connectors which should be salvaged for later use.
Emissions Harness... this harness is located on the passenger side of the engine compartment. It contains wires between the rotary engine's ECU to the rotary's injectors and ECU sensors. Most of this harness is no longer needed, but it also contains wires to the wipers, cruise control, water temp sender, which should be retained when the rest of the harness is removed.


Front Harness Connectors

Connector X-01...is located on the side of the main fuse box, located just ahead of the driverís side strut tower.
...Black w/ white stripe...when the rotaryís engine harness is removed from the car, a vital wire is lost that runs from the 80A fuse in the main fuse box to the large stud (A-04) on the back of the RX-7ís alternator, and also to the ignition switch through a large single terminal connector located between the main fuse block and the driverís strut tower. This wire was originally black w/ white stripe, and very thick, appx. 10ga. Be sure to replace it with wire of at least the same capacity, that connects all three points in the circuit.

Connector X-07... the RX-7's Engine harness connects to the Front harness at X-07, a rectangular plug with 10 conductors (2 rows of 5), located between the left front strut tower and the firewall. Listed below are the wires of interest that can be accessed at this connection:
...Yellow w/ red stripe... this wire goes to the rotary engine's oil pressure sensor. Install this sensor into the Chevy/Ford (the threads are compatible), and your in-dash oil press gauge will work.
...Black w/ yellow stripe... this wire is the power wire to the back-up lite switch, and simply connects to one leg of the switch.
...Red (Red w/ green stripe in engine harness)... this wire goes back to the back-up lites, and connects to the other leg of the switch.

Connector X-05...this connector is at the Fuse box.

Connector X-08...this connector is a 6 conductor (2 rows of 3) located between the firewall and the left strut tower. Wires of interest here are:
...Black w/ green stripe... this wire comes from the starter cut relay (controlled by the anti-theft system), and is the one that energizes the starter to crank the engine over. It can be connected to the Chevy engine's starter solenoid "S" terminal (the small post closest to the block).

Connector X-11... this is a rectangular 15 pin connector (2 rows, 1 of 9, 1 of 11) between the front harness and emissions harness, located in the RX-7's passenger kick panel area. Wires of interest are:
...Blue... this wire provides power to the wiper motor thru a 15 amp fuse at X-07 when the ignition switch is in the "RUN" position. It needs to connect to the plug at the wiper motor if the emissions harness is completely removed.
...Blue w/ yellow stripe... this wire needs to connect to the plug at the wiper motor if the emissions harness is completely removed.
...Blue w/ white stripe... this wire needs to connect to the plug at the wiper motor if the emissions harness is completely removed.
...Blue w/ red stripe... this wire needs to connect to the plug at the wiper motor if the emissions harness is completely removed.
...Black... this wire needs to connect to the plug at the wiper motor if the emissions harness is completely removed. It grounds the wiper motor case.
...Black w/ yellow stripe... these 2 wires are switched by the main relay thru a 40amp main fuse. The ignition switch energizes the relay in the "RUN" position, making it a good source for injector power.
...Black w/ white stripe... these 2 wires are switched by the normally closed side of the starter cut relay, energized from the "START" side of the ignition switch (powered by 80A main fuse). They are also powered by the normally open side of the main relay, which energizes them when the ignition switch is in the "RUN" position thru a 30amp main fuse. They formerly powered most of the rotary engine's emissions and control solenoids and switches.
...Brown... this wire goes to a switch inside of the airflow meter (located ahead of the right front strut tower), and needs to be grounded to make the relay energize the fuel pump. Although simple grounding of this terminal will make your fuel pump operate somewhat normally, We strongly recommend that you ground this terminal through an oil pressure safety switch, so that the fuel pump will not continue to operate should the engine die, or in case of an accident.

Connector B1-04... the tach signal wire is most easily accessed at the B1-04 connector that went to the RX-7's trailing coil, located just in front of the left strut tower:
...Yellow w/ blue stripe... this wire is the tach signal wire.

Connector B3-02... the 2nd gen RX-7s use a circuit opening relay to allow the rotary engine's ECU to control the fuel pump. The relay is located under the dash above the steering column, and has a 6 place connector (2 rows of 3), identified as follows:
...Blue w/ red stripe... this wire provides 12v 15A fused power from the battery.
...Blue w/ green stripe... this wire goes to the fuel pump.

Connector C-02... the C-02 connector is located on the back of the dash pod, on the left (driver's) side. Of the many other wires that are there, the 2nd gen RX-7s also has a speed sensor built into the speedometer head.
...Green w/ red stripe... this is the wire from the speed sensor. It is a reed switch, operated by a rotating magnet at the end of the speedo cable inside the dash pod, so the output is a square wave. The switch cycles open and closed a total of 4 times per revolution, which when combined with the 1025 revolutions per mile of the RX-7, makes a 4100 pulse per mile speed signal. The US standard for speedometers is 1000 rev per mile, which makes for a 4000 PPM signal that is often used by computer controlled engines. The difference between 4000 and 4100 PPM is only around 2%, so further correction is often not required. The other leg of the reed switch is grounded internally, and the signal can be used as a vehicle speed input.

Connector G-03... this 2 connector plug onto the refrigerant pressure switch (located on the right side under the plastic panel in front of the hood latch), in the line between the drier and condenser. Points of interest are:
...Blue... this wire comes from the AC thermostat.
...Blue w/ orange stripe... this wire needs to be connected to a 12v+ ignition power source in order to power the fan amplifier.

Connector G-16... this connector plugs into the AC main relay, located under a plastic panel in front of the hood latch. Wires of interest here are:
...Blue w/ black stripe... this wire is power from the ACC side of the ign switch, fused at 10A.
...Red w/ yellow stripe... is from the blower control unit.
...Black w/ white stripe... this wire goes to the AC compressor clutch magnet.
...Blue w/ white stripe... this terminal/wire needs to be grounded to allow the AC clutch to be energized. It was formerly grounded by the RX-7's ECU.


Emissions Harness

The RX-7's emissions harness provided the main connection between the rotary engine's ECU , it's sensors, and it's fuel injectors. The emissions harness passes thru the RX-7's firewall on the passenger (right) side. It can be removed entirely, except for the wires listed below. The RX-7 ECU, located on the other side of the firewall (on the right side under the passenger floorboard), is no longer needed either. All the wires from the ECU to the RX-7 engine and sensors, located mainly on the right side of the engine bay, can be removed. The wiper wiring runs in the same harness, so split the loom and save the following wires:

The wiper wires...
...Blue...a power wire directly to the wiper motor from the ignition switch's "ignition" position.
...Blue w/ yellow stripe...to the wiper motor from the delay relay.
...Blue w/ white stripe...connected between the switch and wiper motor.
...Blue w/ red stripe...connected between the switch's "hi" position and wiper motor.
...Black...wiper motor ground.

The water temp sender wire...
...Yellow w/ white stripe...

The cruise control wires......
...Green...power wire to coil of actuator's relay. Also powers "cruise" lite in the dash.
...Green w/ black stripe...
...Green w/ white stripe...
...Green w/ yellow stripe...

The Emissions harness can be removed after the above wires are salvaged, but a few of it's connectors should be salvaged to make connecting to the front harness easier. Those connectors are...
X-11...
The description and location of these connectors is listed in the front harness section above.


Next page....

1....Introduction....

2....Considerations & Requirements....

3....Getting Started....

4....Engine / Transmission Installation....

5....Exhaust / Throttle Cable / Accessory Drive / Pulleys....

6....Cooling / Fuel Systems....

7....RX-7 Wiring Harness Connector ID and Circuit Locations....

8....Electrical System Modifications By Circuit....

9....Start-up / Troubleshooting....

10....Upgrades....