6
7
NEXUS R3 CONNECTIONS
+
-
Battery Positive and Battery Negative
(Nexus R3 VCU)
The battery positive and battery negative must be
connected to the Nexus R3 VCU at all times.
Connect the Positive (+) battery terminal to the
Positive terminal (RED) on the Nexus R3 using the
RED SurLok connector provided and a RED 4AWG
battery cable (sold separately).
Connect the Negative (-) battery terminal to the
Negative terminal (BLACK) on the Nexus R3 using
the BLACK SurLok connector provided and a BLACK
4AWG battery cable (sold separately).
A
C
E
Nexus R3 VCU Connection
With the unit powered off, connect the 3 VCU plugs
on the main harness to the Nexus R3:
Ignition Switch
(Label: Ignition Switch)
The ignition switch input (pink) wire must be
connected to a sw12V source to turn the
Nexus R3 on. If wiring to an ignition key switch, it
is important to make sure to connect to the main
ignition wire (i.e. not accessory) so it doesn’t loose
power while the engine is cranking causing the VCU
to momentarily turn off.
Alternatively, the pink and red/blue wires, labelled
together as “Ignition Switch” in the harness can be
connected to a switch to turn the VCU On or Off.
NOTE: The red/blue wire is a low c12V
source (from pin A26) and must not be used to
power any other device in the vehicle. Insulate and
isolate if not used.
Crank (Trigger) and Cam (Home) Inputs
The crank and cam position sensors are required
so that the ECU has the necessary information
available to determine engine speed and position at
any point in time. Generally there are two types of
sensor for these inputs:
Hall Effect / Optical sensor
This type of sensor sends out a digital square wave
signal. Hall Effect sensors will usually have three
pins - signal, signal ground, and a +12V power
wire which is supplied by HBO5 in this harness. A
+8V supply and a +5V wire is also available in the
harness if required.
Reluctor sensor
This type of sensor sends out a sine wave type of
signal. Reluctor sensors do not require external
power. These sensors can generate their own
voltage signal as the sensor reads a moving tooth
or trigger.
This harness uses a four-core shielded gray cable
for the crank (Trigger) sensor, and a four-cour
shielded gray/black cable for the cam (Home)
sensor. Shields are already connected to the power
ground wire within the harness and will not require
further grounding. Refer to the diagram below
for wires required to connect to a Hall Effect or
Reluctor senor.
Specs:
• -10V to +10V input
• Selectable 1k2 or 440R pull-up to 5V
• Selectable ground reference
(full differential standard mode)
• -75 to +75V indefinite withstand
• 48kHz max signal frequency
indicates not connected. Please insulate and isolate to avoid damage to the ECU.
+12V (HBO5)
SIGNAL GROUND
CRANK (T)
CRANK (TRIGGER -)
HALL
SENSOR
EFFECT
RELUCTOR SENSOR
+12V (HBO5)
SIGNAL GROUND
CRANK (T)
CRANK (TRIGGER -)
BATTERY
ACCESSORY
IGNITION
START
IGN SW INPUT
IGN SW INPUT
(LOW CURRENT)
SWITCHING THE VCU ON (METHOD 1)
SWITCHING THE VCU ON (METHOD 2)
+12V
Connector A:
34-pin, Keyway Type 1
Connector C:
34-pin, Keyway Type 2
Connector E:
4-pin, DTP
Battery Ground Output
The battery ground output wires are capable
of sinking 3A per pin on the Nexus R3 and are
directly linked to the battery negative stud internal
to the VCU.
These wires can be used for cable shielding
connections or to ground low current CAN devices,
digital sensors, or switch grounds.
WARNING! The battery ground output wires are
NOT meant to ground the VCU and should not be
connected to battery negative or to the engine or
chassis.
SAMPLE USE OF THE
BATTERY GROUND OUTPUT
AVI
BATTERY
GROUND
OUTPUT
HIGH / LOW
BOOST
SWITCH
