Dakota Digital VHX-78C-MC, Manual

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MAN 650314:D 11
OIL –
This is the ground reference used for three-wire pressure sensor. This will connect to the
black wire as well as the bare silver shield wire from the Dakota Digital SEN-03-8.
***The bare wire is the shield wire, connect this wire to the OIL – along with the BLACK
wire
***DO NOT connect this terminal to any other devices
FUEL +
This output is not typically used. It is a low c12V supply for powering solid state
fuel sensors. Currently, it does not have an application for any Dakota Digital fuel level sensors.
***This terminal should not be used with a typical resistive type fuel sensor. For
most applications, leave this terminal open. Do not try to power other devices from this
terminal or damage to the control box will occur.
FUEL SND
The fuel gauge sending unit is not normally supplied because the display system can use
the existing fuel sending unit in the tank in many cases. The sending units that are compatible
with this system are as follows: GM, Ford, VDO, and Stewart Warner. It is also possible to
program a custom setting for senders that are not pre-programmed into the system.
Use the FUEL - and FUEL SND terminals and run a twisted pair of wires back to your fuel
level sensor. Connect the FUEL - terminal to the fuel level sensor body or a mounting screw to
insure the sensor is sufficiently grounded. The other wire is the sensor signal which goes to the
FUEL SND terminal.
If your wiring harness already has a single wire routed through the vehicle for the fuel
sender then it may be used. If using a wire from an existing harness, make sure that the wire
does not have power. The fuel sender gets power from the control box only. Fuel senders
reference their ground from the sender mounting plate.
The fuel sender type is selected using the fuel setup menu under “ SENDER ”. The settings
are discussed later in the setup section. Anytime the fuel level is below 10%, the reading will
flash as a warning of low fuel.
The fuel gauge will initially display “ E ” until the fuel sender type has been set, and a
message will be displayed that says to “
set Fuel sender
”. If the message display shows “
---
%FUEL ” this indicates that the control box is sensing a short to ground or out-of-range error from
the sender or sender wire. If the message display shows “
EEE %FUEL
” this indicates that the
control box is sensing an open circuit or out-of-range error from the sender. If either indication
remains on the display, inspect the sender wire for damage, check the routing of the sender wire,
check the sending unit grounding, and check that the sender selection is set correctly for the
sending unit that is connected.
FUEL –
Connect the FUEL - terminal to the fuel level sensor body or a mounting screw to insure
the sensor is sufficiently grounded. One terminal on the sensor is the signal which goes to the
FUEL SND terminal.
***For fuel level sensors that are attached to an electric fuel pump, or if you have an
electric fuel pump in the tank, make sure that the fuel pump is externally grounded to the
vehicle chassis. Attempting to ground the fuel pump to the Dakota Digital control box will
result in erratic operation and damage to the control box.