Wiring your 7M Supra engine

Wiring your V6 89-95 Toyota truck or 4Runner conversions using an 89-newer 7M ECU and harness

After you have run your wires through the firewall, you should have several connectors just hanging out near where your ECU would have been(assuming your pulled it out. There will be 9 connectors in all. 7 connectors are for the supra engine harness, and 2 connectors for the vehicle harness.
The two vehicle connectors in the passenger side kick panel should be gray. These connectors are IH1, and IH2. IH1 is larger than IH2. IH1 is generally used for ECU related stuff, and the IH2 connector is used for other stuff like guages.

On the supra engine harness, there are three slim yellow connectors that are somewhat identical except the width. These connectors are for the ECU, and you don't have to worry about any of those. Then there is a large yellow connector, small yellow connector, a white connector, and a black connector. The white connector is only used if you are using an auto tranny, so most of you can just leave that one be. The black connector is used for the HAC, or High Altitude Compensation sensor. This is used in applications above 5,000ft. You will get an engine code if this is not used, but will not affect how it runs. Try to get the sensor though. In a supra, it is located just behind the glove box, bolted near the base of the glove box.

That leaves just two other yellow connectors that you need to deal with inside the cab. M1 and B1

The large yellow connector(B1) - is where you supply power, starter signal, speed sensor, and fuel pump signal.
The smaller yellow connector(M1) - is the easiest. From here, you will get oil pressure, water tempurature, and the engine light.

Large Yellow Connector(B1)

B+ Power

There should be a White/Red wire in the IH1(16) connector. This should recieve power when the EFI main relay is turned on. Test this before you start. Turn the ignition on and check for power. If you have power, pull the EFI Main and check to make sure you lost power. If so, you have the right wire, this will be your B+ wire. You need to tap into this wire, and connect it to the black/red wire on the B1(7).

Component Power

There should be two black/orange wires on the B1 connector. One should be large guage, the other should be small. The small guage black/orange(could be grey instead)wire is your ignition switch wire B1(9), and will be delt with later. It will be connected to a wire coming from the fuse box in the engine compartment. The other thick guage black/orange wire B1(14) supplies power to most of your engine components. You will get this wire from the IH1 connector too. This wire will be a black/red wire on the IH1(14) connector

Starter

The starter signal wire is the large guage Black/white wire B1(10). This could be Black/blue if you are running an automatic. If this is the case, you need to connect this whire with the Black/White wire at the transmission connector plugs. These will be under the intake manifold. The black/white wire at the B1 connector needs to be connected to the large guage black, or black/white wire on the IH1(22) truck/4runner harness. Then on the B1 connector, you will also find a small guage black/blue wire, B1(5). You will tie this into your starter signal. This will tell the ECU that you are stating the engine.

Fuel pump - turbo only

The fuel pump is a green wire on the B1(4) connector. You need to connect this to the green/yellow on the IH1(23) connector. Again, this will supply a ground signal to your Circuit Opening Relay.

Small Yellow Connector(M1)

Oil Pressure

Oil pressure will be the yellow/black wire on the M1(7) connector. This will connect to the yellow/light blue wire on the IH2(11) connector

Water Temperature

Water tempurature will be the yellow/green wire on the M1(10) connector. This will connect to the yellow/green wire on the IH2(14) connector

Engine Light

Engine light will be the grey/green wire on the M1(8) connector. This will connect to violet or dark blue wire on the IH2(3) connector

Speed Sensor

This is the pink wire on the M1(3) connector, but could turn into a yellow/red wire when it passes through the B1 connector. You need to connect this to the green/blue wire on the IH1(20) connector.

C1 connector by igniter

2 wires will be used from this connector - only one required

The black/yellow wire needs to be connected directly to your battery. Don't forget to use a 7.5 amp fuse.

After reading the next paragraph it is too complicated and/or you just don't want to mess with it, the don't do it. Just allow the ignition to control your EFI main.

The black/orange wire will go to your EFI MAIN RELAY. The EFI main is located in the fusebox in the engine compartment. This will require running a wire from the C1 connector across the firewall, and to the fuse box. At the fusebox, you will need to cut the black wire with the yellow stripe, feeding into the EFI MAIN RELAY, best access is under the fuse box. You will need to solder the wire from the C1 connector to the black/yellow wire that goes to the EFI Main. The other side of the black/yellow wire, under the fusebox, needs to connect to the B1 connector inside the cab. Solder a wire to here, and run it into the cab. This wire will then connect to the small guage black/orage wire on the B1 connector.
E-mail me at robertj@linux4free.com for questions about this that you don't understand, so I can try to exlain it better.