Dakota Digital VHX-78C-MC, Manual

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MAN 650314:D 30
Symptom Possible Problem Solution
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The tachometer reading
The tachometer signal wire is Check the connections at both
is incorrect. loose or broken. ends of the wire.
The engine cylinder setting is Refer to the “Tach Setup” section
incorrect. of the installation manual.
The speedometer will
The speed signal is not Check that all speed sending
not show a reading. connected to the control box unit wires are connected to the
properly. control box properly.
The speed signal being used is Use the speed sending unit
not compatible with the control supplied with the display
box. system.
The speed sending unit is not Check that sender is mounted
connected to the transmission properly.
properly. Check that transmission has the
appropriate internal parts.
The sending unit wire is picking Isolate the sending unit wire from
up noise from nearby wires. motor and ignition wires.
The speedometer is reading The speedometer is not calibrated. Refer to the “Speed Calibration”
too fast or too slow.
section of the installation manual.
With the engine running and A tachometer wire is too close to
Reroute or isolate the tachometer
the vehicle sitting still, the to the speed signal wire. wire away from the speed wire.
speedometer reads higher There is a ground problem between Make certain the ground wire for
than zero.
the speed sensor and the control the speed sensor is connected
box. directly to the control box ground.
A display shows “EE”
Sending unit for that gauge Check the wire from sending unit
is not connected to the control to the control box for breaks.
box. Make sure that the sending unit is
wired to the correct terminal.
Sending unit is not getting Make sure the sending unit is
grounded. grounded properly at the control box.
On the water or oil, the sending Use the water and oil senders that
unit is not the correct type. were supplied with the system.
On the fuel, the control box may be Refer to “Fuel Setup” section of the
set for the wrong fuel sender. installation manual to ensure that
the settings match your fuel sender.
A display shows “- -”
The sending unit wire for that Repair or replace shorted wire.
gauge is shorted to ground.
Sending unit for that gauge Check the wire from sending unit
is not connected to the control to the control box for breaks.
box. Make sure that the sending unit is
wired to the correct terminal.
Fuel displays “ ? ”
The control box is set to an invalid Refer to “Fuel Setup”
and gauge stays at fuel sender setting. section of the installation manual
empty. to ensure that the settings match
your fuel sender.