The LS1 harness basically connects to the rest of the car thru a few specific connectors. The first four are located in the area of right shock tower...
...C100...black 10 pin connector.
............A- pink (bank 1 ign/inj switched 12v 15amp power in)
............G- pink (transmission/EVAP switched 12v 15amp power in)
............H- dk blue (cooling fan "hi speed" relay control out)
............J- dk green (cooling fan "low" relay control out)
...C101...grey 10 pin connector.
............B- pink (bank 2 ign/inj switched 12v 15amp power in)
............D- dk green w/ white stripe (fuel pump relay control out)
............E- pink w/ black stripe (switched 12v 15amp power for PCM in)
............G- orange (constant power for PCM 12v 50amp power in)
............H- black w/ white stripe (ground in)
...C102...
............A- purple (starter solenoid "start" power in)
...C105...black 8 pin connector.
............B- pink (trans/stop lamp/heated o2/MAF 12v 20amp power in)
............G- white (tach signal out)

The other two are located behind the firewall, inside the passenger compartment, on the other side of the firewall grommet.
...C220...natural color 10 pin connector.
............E- black w/ white stripe (ground in)
............G- brown (to back-up lite switch 12v"+" power input)
............H- lt green (from back-up lite switch out to lites)
............K- dk green w/ white stripe (VSS signal 4000ppm speedo output from LS1 PCM)
...C230...blue 10 pin connector.
............B- brown w/ white stripe (MIL lamp)
............E- dark blue (VATS fuel enable input)
............K- dk green (serial data class 2 output from LS1 PCM to OBD-II connector)

The only other two points that the LS1 harness needs connected are down by the LS1's starter...
...purple wire... needs to be connected to the starter solenoid's "S" terminal.
...open ground lug... needs to be connected to a block ground.

The GM color code for wiring is very consistant. When in doubt, the following applies to any loose ends you might end up with in connectors C100, C101, C105, C220, and C230...
...red wires...all loose red wires should be connected to "12v+" protected by a fusible link.
...orange wires...all loose orange wires should be connected to "12v+" protected by a fuse of at least 10a.
...pink wires...all these wires in the LS1 harness should connect to a 12v "switched +" power source hot in "start" and "run".
...black...all these wires in the LS1 harness should connect to chassis ground.
...black w/ white stripe...all these wires in the LS1 harness should connect to engine ground.

Re-connecting The Battery To The RX-7's Harness... The battery, the large top terminal on the Chevy starter solenoid, the RX-7's power distribution block, and the large terminal on the back of the alternator need to all be connected to each other with large wire of at least 6ga size. When your battery is re-located to the rear of the car, this large gauge wire should extend all the way to the battery "+" terminal.
Be sure to connect the chassis and block together with a large ground cable of at least "00" guage, as the engine/trans are somewhat isolated by the rubber engine/trans mounts. Without a large seperate ground wire, smaller ground wires will become overloaded and possibly melt during periods of hi current draw, such as when the starter is engaged.

Starter Wiring...The wiring for the LS1 starter is almost identical to that of the RX-7. The problem is that the RX-7 starter solenoid's "start" wire was part of the engine harness, which was removed with the rotary engine. You can access this black w/ white stripe wire at the small 4 pin grey X-11 connector located in front of the driver's side strut tower.
...Manual trans applications...Route a wire from the RX-7's X-11 connector's black w/ red stripe wire that extends to the LS1 harness connector C-102's "A" terminal (purple wire).
...Automatic trans applications...Route a wire from RX-7's X-11 connector's black w/ red stripe wire that extends thru the neutral safety switch, then to the LS1 harness connector C-102's "A" terminal (purple wire). Be sure that the neutral safety switch interrupts this wire in all shifter positions except neutral and park. If it does not, adjust the switch until it does.

Ignition Wiring...Power for your LS1's ignition and injectors is supplied by connecting 12v "switched" power to the C-100's A terminal (pink wire) and to C-101's B terminal (pink wire). Chevy gave each circuit a seperate 15amp fuse. Switched 12v 30amp power from the RX-7's EGI Main Relay can be tapped from either the RX-7's X-05 connector's black w/ white stripe wire (located in the passenger footwell area) or the RX-7's ECU plug B1-01 connector's black w/ white stripe wire, or directly from the bottom of the RX-7's EGI Main Relay's B1-02 connector's black w/ white stripe wire, located inside the RX-7's power distribution center located on the driver's side shock tower.

Eliminating The RX-7 Fuel Pump's "high-speed" Relay & Resistor...The 3rd gen RX-7's fuel pump was controlled by it's ECU, which grounded the coil in the circuit opening relay (blue w/ black stripe wire) to turn the fuel pump on. When the rotary seen boost conditions, it's ECU upped the voltage to the fuel pump by grounding the coil in the fuel pump "hi-speed" relay (blue w/ white stripe wire), causing the relay to bypass the fuel pump resistor, increasing fuel pump voltage. Many simply wire around the resistor or eliminate the fuel pump relay and resistor altogether to acheive maximum fuel pump output at all times. We prefer to eliminate the RX-7 fuel pump resistor and fuel pump "high-speed" relay altogether by unplugging the relay's B1-04 connector and connecting the fuel pump's white w/ red stripe wire directly to the circuit opening relay's blue w/ red stripe wire (both wires are in the B1-04 connector). With these wires connected, the RX-7's fuel pump resistor and fuel pump "high-speed" relay are no longer needed, and can be simply removed and discarded.

Modification to the wiring for the RX-7's Circuit Opening Relay (fuel pump relay)...Located inside the relay/fuse box located on the RX-7's right side shock tower. Required to enable the LS1's PCM to control the fuel pump. Basically we are changing from a ground enabled control to a power enabled system. Locate the black w/ lite green wire in the Circuit Opening Relay's B1-03 connector. This wire needs to be cut in two about 3" back from the connector, inside the harness. Tape and insulate the end of this wire coming from inside the harness, as it is no longer needed. The other end of the cut wire that comes from the Circuit Opening Relay needs to be connected to ground. Connect the other side of the Circuit Opening Relay's coil, a blue w/ black stripe wire in RX-7 connector B1-01 terminal 1T, to the LS1 connector C-101's terminal D, a dark green w/ white stripe wire.

RX-7 Dash Harness Ground...this connection is important for functioning gauges and dash lites. The connection is different depending on what transmission your RX-7 originally came with.
...manual trans from factory...ground large black w/ blue stripe wire in salvaged emissions harness side of RX-7 connector X-14. If you are working with the front harness half of this X-14, this wire changes to black.
...automatic trans from factory...ground the black w/ blue stripe wire in RX-7 connector X-05, a blue 22 pin connector located behind the firewall in the passenger footwell area, below the RX-7's X-14 connector.

Temp Sender Location & Installation...The RX-7's rotary engine's temperature sending unit for the dash gauge is a very small single terminal device located below the rotary engine's oil filter. It can be removed from the rotary and installed in your V-8' cylinder head (in back of rear exhaust port on passenger side) using a special reducing bushing. After installation, the sending unit should be connected to the yellow w/ white stripe wire in the salvaged emissions harness half of RX-7 connector X-14. If you are tracing the dash harness side of X-14, this wire changes to grey. The original connector for the rotary temp sending unit can be salvaged from the discarded emissions harness and re-used here for a factory quality connection.

Oil Pressure Sending Unit Wiring... The rotary engine's oil pressure sending unit for the dash gauge is a large round single terminal device located below the rotary engine's oil filter. It can be removed from the rotary and installed in a drilled and tapped hole (1/8" npt) in the small removable cover located just above the LS1's oil filter (retained by 2 bolts w/ 10mm heads) using two 1/8" pipe thread 90 degree elebow fittings (male threads for the block, female threads for the sender) to angle the sender away from the exhaust. A single wrap of the threads with teflon tape should ensure leak free operation. After installation, the sending unit should be connected to the grey w/ red stripe wire in connector X-12. The original connector for the sending unit can be salvaged from the discarded emissions harness and re-used here for a factory quality connection.

LS1/Delco Alternator Wiring...The LS1 alternator output is triggered by a low voltage signal from the LS1 PCM's C-2 "red" connector, pin 15. This wire is contained within the stock LS1's engine harness. The '99-newer LS1 had proper control of the voltage regulator incorporated into the PCM. The '98 LS1 PCM did not, and the circuit needs modification to prevent alternator damage. For proper operation, alternator terminal "L" (red wire) needs to go thru a 470 ohm resistor. Simply snip the red wire at a conveinant location, and solder the resistor in series with the wire. Shrink tube should be used to seal the modification and to help prevent mechanical fatique in the resistor's leads.

RX-7 Cooling Fan and Relay Control by the LS1 PCM...These wiring mods allow controlling the '93-'95 RX-7's existing cooling fans and relays with the LS1's PCM. The RX-7's four cooling fan relays are located together on the inner fender panel, just ahead of the right side front shock tower.
...LOW SPEED OPERATION-
connect all three of the following RX-7 relay terminals to LS1 connector C100 pin J (dark green wire)...
......RX-7 relay #1 (upper/forward relay, connector B2-01), connect the terminal with the V/P wire (violet w/ pink stripe)
......RX-7 relay #2 (upper/rear relay, connector B2-02), connect the terminal with the G/B wire (green w/ black stripe)
......RX-7 relay #4 (lower/forward relay, connector B2-04), connect the terminal with the G/B wire (green w/ black stripe)
...HI SPEED OPERATION-
connect the following RX-7 relay terminal to LS1 connector C100 pin H (dark blue wire)...
......RX-7 relay #3 (lower/rear relay, connector B2-03), connect the terminal with the L/G wire (blue w/ green stripe)

Speedometer Signal Wiring...The RX-7's speedometer originally got it's signal from a generator mounted on the driver's side of the RX-7 transmission's tailhousing. The easiest way to correct this is to use a "digital ratio adapter", such as the Dakota Digital SGI-5C, which is wired as follows...
...SGI-5C POWER...connect to RX-7 B1-01 ECU plug terminal 1B, a 12v switched power source that comes thru the RX-7's main "EGI" relay.
...SGI-5C GROUND...connect to the salvaged emissions harness side of RX-7 X-14 connector's orange wire (wire color changes to yellow w/ white stripe on the dash harness side of X-14). This wire should also be connected to a good chassis ground such as one of the former RX-7 ECU mounting studs.
...SGI-5C INPUT...connect to LS1 harness C-220 connector terminal "K", a dark green w/ white stripe wire that comes from the LS1 PCM's 4000ppm VSS signal output.
...SGI-5C OUT 3...connect salvaged emissions harness half of RX-7 X-14 connector's green (manual trans) or green w/ black stripe (auto trans) wire (wire color changes to yellow w/ red stripe on the dash harness side of X-14). Use output 3, and set the dip switches as follows...
......dip #1- on
......dip #2- on
......dip #3- off
......dip #4- on

Tachometer Signal Wiring...The RX-7's tachometer originally got it's signal from the rotary engine's ECU. The stock rotary engine put out a tach signal that was the same rate as a 4 cyl piston engine. The LS1's PCM puts out a 1/2 rate tach signal for a V-8. Simply using the LS1's tach signal to drive the RX-7 tach will result in a correct reading tach. Connect the LS1 PCM's blue connector terminal 35 (white wire in connector, "tach signal output") to the RX-7's B1-01 ECU plug terminal 2B, a yellow w/ blue stripe wire (formerly the signal input point for the RX-7's tach).

Back-up Lite Switch...to operate the RX-7's back-up lites, Mazda used a transmission mounted SPST switch to complete the circuit. When the RX-7's emission harness is removed with the rotary engine, part of this circuit is removed as well. To restore this circuit, a 2 wire harness extension to the new reverse switch will need to be added from connector X-14, a rectangular 2 row 14 wire connector (1 row of 6, 1 row of 8, 2 wires missing) between the "emissions" and "dash" harness, located under the dash in the passenger footwell area. 2 of the wires in this connector are for the back-up lite switch. Wire colors for this circuit change as they pass thru X-14. If you are tapping into X-14 by salvaging the discarded male emissions harness side of X-14, these wire colors are...
...green w/ yellow stripe (manual trans) or black wire w/ yellow stripe (auto trans)...from 15a fuse in underdash fusebox.
...yellow w/ red stripe (manual trans) or brown w/ black stripe (auto trans)... goes to RX-7's back-up lites.
Simply connecting these 2 wires together will turn on your RX-7's back-up lites. Specific back-up lite switch wiring detail depends on which transmission you are using.
...T-56 transmission, the reverse lite switch is located on the right (passenger) side of the transmission's main case, about in the center. The LS1 engine harness contains a connector and wires for the switch that come out at LS1 connector C220. A short connector harness can be easily made that connects the RX-7's X-14 and the LS1's C220 connectors as follows...
............RX-7 X-14 green w/ yellow stripe (manual trans) or black wire w/ yellow stripe (auto trans)...from 15a fuse in underdash fusebox. Connect to LS1's C220 connector terminal "G", a brown wire.
............RX-7 X-14 yellow w/ red stripe (manual trans) or brown w/ black stripe (auto trans)... goes to RX-7's back-up lites. Connect to LS1's C220 connector terminal "H", a lite green wire.
4L60E transmission, the reverse light switch was located on the Camaro/Firebird's shifter, not on the transmission. To get your reverse lights working, you will need to add a switch to whatever shifter you use, and wire it into your RX-7's X-14 connector.

Low Coolant Level Warning Buzzer and Lite...the warning buzzer was an absolute necessity for the rotary engine, but is generally not worth the trouble when installing a LS1. To dis-able the annoying coolant alarm buzzer, simply ground the brown w/ white stripe wire in connector X-12.

LS1 VATS Anti-Theft System...The GM Vehicle Anti-Theft System (VATS) is not used here, but the proper enable signal must be fed into the LS1's PCM to enable the engine's injectors to allow engine start-up. We use a "VATS Eliminator Box" that creates the proper 50hz square wave signal for the LS1's C2 PCM connector's terminal 30 (dark blue wire) necessary to enable engine operation. The VATS Eliminator boxes usually have 3 wires, that need to be connected as follows...
red wire...connect to 12v hot in ign/start.
black wire...connect to ground.
green or blue wire...connect to LS1 C-230 connector terminal E (dark blue wire).
An alternative method is to remove the VATS requirement using an edit program for the LS1's PCM.

T-56 "Skip Shift" feature elimination..."skip shift" is an annoying feature GM came up with for the 6spd cars that essentially forces you to "skip" gears under certain conditions in an attempt to improve fuel economy. If you simply unplug the solenoid connector, the LS1 PCM will throw a "DTC P0803" code, which will result in triggering the "MIL" lite. This function can be easily eliminated by simply installing a 2.2k ohm resistor across the wires that formerly went to the skip shift solenoid, located on the driver's side upper part of the T-56's main case. Colors for the 2 wires in this connector are...
......grey...
......pink...
We recommend unplugging and cutting off the harness connector for the solenoid, and simply soldering the 2.2k resistor across the cut wires extending from the harness. Be sure to insulate your work with either tape or, as we prefer, shrink tube.

AC System- Relay, Compressor & Pressure Switch...Only 2 circuits need modification for your AC system to function properly.
...AC relay (G-02)... in the #2 position in the relay box located in the nose of the car just to the passenger side of the hood latch. It has a square connector with 4 wires attached. It's terminals need to be re-connected as follows...
......blue w/ black stripe wire...connect this wire to one leg of the RX-7's pressure switch located near the RX-7's reciever/drier. The other leg of the pressure switch connects to "12v +" thru the "AC ON" switch.
......yellow w/ black stripe wire...connect this wire to ground.
......black w/ red stripe wire...connect this wire to the "+" side of your compressor's magnetic clutch. Connect the other leg of the magnetic clutch coil goes to ground.
......yellow wire...connect this wire to a "12v ign on" power source.
...AC pressure switch...a 2 terminal switch located next to the RX-7's reciever/drier. The switch's harness connector can be clipped from the front harness and re-used. The 2 legs of this switch/connector can re-wired as follows...
......violet wire...connect to "12v +" thru the "AC ON" switch.
......grey w/ red stripe wire...connect to the AC Relay's blue w/ black stripe terminal.

OBD II Connector...this under-dash connector is not necessary to run your car, but it will be necessary to access the PCM's diagnostic features and will be required to pass a smog inspection. The OBD II connector was not part of the LS1's engine harness, but can be easily obtained from most '98 or newer cars in a wrecking yard. Simply attach the OBD II connector body under your RX-7's dash in an accessable but inconspicous place, then make the connections listed below. This 16 pin connector is arranged in 2 horizontal rows of eight, with the top row numbered left to right 1 thru 8, and the bottom row numbered 9 thru 16. The necessary connections are listed below...
...pin 2 (purple wire)- class 2 serial data. Connect to LS1 harness connector C230 pin "K" (dk green wire)
...pin 4 (black wire)- connect to chassis ground
...pin 5 (black w/ white stripe wire)- connect to engine ground
...pin 16 (orange wire)- connect to battery "12v+" constant power source.
The rest of the OBD II connector's terminals are not used.

Malfunction Indicator Lamp (MIL)...although not necessary to run your car, a working "MIL" will be required to pass a smog inspection. Your RX-7's dash display contains a "MIL" lamp, which can be controlled by the LS1 PCM by following a few simple steps...
...STEP 1-...Locate your RX-7's "electrical load control unit" (ELU), located in the passenger kick panel area in front of the passenger side door hinges.
...STEP 2-...Unplug RX-7 connector B1-20 from the ELU. B1-20 is a rectangular black 16 pin connector (2 rows of 8), with only 8 wires and 8 empty slots. Wire colors are...
............black...
............orange w/ black stripe...(grounding this wire will illuminate RX-7's MIL lamp)
............orange w/ blue stripe...
............black w/ white stripe...
............white...
............white w/ black stripe...
............tan...
............grey...
...STEP 3-...The ELU itself is no longer needed, and can now be removed and discarded (it's former function was to increase the rotary engine's idle speed when certain electrical accessories were activated).
...STEP 4-...connect RX-7 connector B1-20 pin "K" (orange w/ black stripe wire) to LS1 connector C-230 pin "B" (brown w/ white stripe wire). The other 7 wires in RX-7 connector B1-20 are no longer used.

This guide will help you locate and identify the RX-7 harness connectors for required connections and modifications...

...X-1 Main Fuse Block...is the power distribution and fusible link block that was formerly located on the positive terminal of the RX-7's stock battery.

...X-02 Relay and Fuse Block...is the fuse and relay box that is located on the driver's side shock tower that contains the fuel pump relay, EGI main relay, and fuses for the AC, ABS, defroster, and cooling fans.

...X-05 Connector...is a blue connector located in the passenger footwell area. The actual connector size is different depending on if the RX-7 was originally equipped with a manual trans or an automatic trans.
............manual trans...12 pin connector
............automatic trans...22 pin connector

...X-11 Connector (location pictured on right)...is a grey 4 pin connector located in front of the driver's side shock tower.

...X-12 Connector (location pictured on right)...is a grey 12 pin connector located in front of the driver's side shock tower.

...X-14 Connector (location pictured on right)...is a white 14 pin (manual trans) or 18 pin (auto trans) connector located under the dash behind the blower motor, behind the glove box, near where the harness passes thru the RX-7 firewall on the passenger side. The female side of X-14 is attached to the dash harness. The male side is is attached to the emissions harness, and is removed with the rotary engine ECU. We suggest that you retain the male emissions half of X-14, along with a section of connected wires, as an easy way to access X-14 without having to work upside down under the dash. Be warned that several wires change color as they pass thru X-14, which can cause confusion, and that wire colors and wire locations within the connector are different depending on if your RX-7 was originally equipped a manual or automatic transmission.

...B1-01 ECU Connector...is a 22 pin connector that plugged into the rotary engine's ECU that was located on the passenger side behind the kick panel

...B1-02 EGI Main Relay Connector...is located under the EGI Main Relay in the Relay and Fuse Block located on the RX-7's driver's side shock tower.

...B1-03 Circuit Opening Relay Connector...the Circuit Opening Relay is inside the Relay and Fuse Block, located behind the battery in front of the RX-7's driver's side shock tower. It's the large green relay labeled "EFI". This is also functions as the main fuel pump relay.

...B1-04 Fuel Pump "hi-speed" Relay Connector...is located inside the plastic box in front of the radiator on the passenger side, near the right headlite.

...B1-05 Fuel Pump Resistor Connector...located under the brake master cylinder, looks like a finned aluminum box w/ 2 wire connector going to it...
......blue w/ red stripe...
......white w/ red stripe...

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....

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