FT500 SFI / FT500LITE SFI
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Electrical installation
8. Electrical installation
As FT500 wires are fully configurable according to the installation
needs, it is very important that the step by step guide shown on
chapter 5 is followed before starting the electrical installation. This way
the wiring harness connection table is automatically filled as shows
the example below:
In the FTManager, to check all the inputs and outputs, go to “Sensors
and Calibration” menu, then “Inputs” or “Wiring harness diagram”.
Through the touchscreen interface, you can access this function in the
“Engine Settings”, then “Wiring harness diagram”.
White 2: 2-step
White 3: Air conditioning
White 1: O2 sensor #1
White 5: Engine temperature
White 4: Oil pressure
Wiring harness diagram
Wiring harness diagram
Blue 1: Primary fuel inj. - cylinder 1
Blue 2: Primary fuel inj. - cylinder 2
White 11: TPS
Blue 4: Primary fuel inj. - cylinder 4
Blue 3: Primary fuel inj. - cylinder 3
Grey 2: Ignition - cylinder 2
Grey 4: Ignition - cylinder 4
Grey 3: Ignition - cylinder 3
Wiring harness diagram
Blue 8: Shift Alert
Grey 1: Ignition - cylinder 1
Yellow 2: Fuel pump
Yellow 4: Available
Yellow 3: Electric fan #1
Wiring harness diagram
Yellow 1:
valve
PWM
Grey 8: Tachometer output
Based on this information, you can start the electrical installation that
must be done with the ECU disconnected from the harness and the
battery disconnected from the vehicle. It is very important that the
cable length is the shortest as possible and that exceeding unused
parts of wires are cut off.
Choose an appropriate location to affix the module inside the car, and
avoid passing the cable wires close to the ignition wires and cables,
ignition coils and other sources of electric noise.
DON’T EVER, under any circumstance, install the ECU near ignition
modules in order to avoid the risk of interferences.
Electric cables must be protected from contact with sharp edges on the
vehicle’s body that might damage the wires and cause short circuit. Be
particularly attentive to wires passing through holes, and use rubber
grommets/protectors or any other kind of protective material to prevent
any damage to the wires. At the engine compartment, pass the wires
through places where they will not be subject to excessive heat and
will not obstruct any mobile parts in the engine.
Red wire - 12V input
Being the 12V input to FuelTech ECU, this wire must be connected to
12V from a relay (Main Relay) and cannot be shared with the positive
wire that powers coils, fuel injectors or other actuators.
• 12V for sensors:
use a 24 AWG wire from the same 12V wire that
feeds the ECU (Main Relay). Example: Hall Effect sensors, pressure
sensors, speed/RPM sensors, etc. This wire cannot be shared with
the positive wire that powers coils, fuel injectors or other actuators.
• 12V for fuel injectors:
use a 14 AWG wire connected to a 40A
relay. Protection fuse must be chosen according to the peak current
of the fuel injectors plus a 40% safety coefficient.
Example: for up to 4 injectors that draw 1A of current per injector
on primary bank, and 4 injectors that draw 4A of current per injector
on secondary bank:
(4x1A)+(4x4A)=20A + 40% = 28A. Use a
30A fuse.
•
12V for coils, fuel pump and other high power actuators:
use
a wire with at least 14 AWG connected to a relay and a fuse correctly
dimensioned according to the actuator current draw. When using
individual coils (COP), it is recommended a 70A or 80A relay.
NEVER
share the 12V that feeds injectors, coils or other accessories,
because, after shutting the engine off, there is a risk of reverse current
that may damage a sensor or the ECU.
Black wire - Battery’s negative
This wire is responsible for signal ground to the ECU so, it must be
connected
straight to the battery’s negative terminal
, with no
seams.
Under no hypothesis, this wire can be connected to the
vehicle chassis
or split with the ECU black/white wire (power ground).
This will cause electromagnetic interference and other problems hard
to diagnose and solve.
The black wire must have permanent contact with the battery’s negative
terminal, never being connected to switches, car alarms or others. To
turn a FuelTech ECU off, the red wire should be switched on and off.
•
Negative for sensors
(TPS, air temp., pressure, rpm, distributor,
etc.): It is vital to use sensors ground straight to the battery’s
negative terminal. Connecting them to chassis may cause
electromagnetic interference, wrong readings or even damage
to the sensors.
•
Attach the negative wires to the battery terminal use ring terminals
and avoid soldering them. A well crimped terminal has better
resistance than a soldered one. Besides that, solder makes the
joint stiffer, and less resistant to vibration, typically found in
automotive applications.
•
Use a crimping tool and insulate the wire with insulating tape or
heat shrink tubing.
