MAN# 650028
POWER
Connect the red wire from the main harness to accessory power from the ignition switch.
Never connect this to a battery charger alone. It needs to have a 12 volt battery connected to it. Battery
chargers have an unregulated voltage output that will cause the system to not operate properly.
GROUND
The black wire is the main ground for the gauge. A poor ground connection can cause improper or erratic
operation.
TACHOMETER
The gray wire connects to the vehicle tach signal. On point type and pointless distributors, connect to the
negative side of the coil. This will sometimes be labeled TACH or DIST. On distributorless ignition systems,
connect to the tach output wire or to the negative wire of one of the coils. On MSD ignition systems connect to the
tach output terminal.
For tach signals integrated into a vehicle wiring harness, consult a service manual to determine the color
code and location of the tachometer signal. The tachometer signals from some engine computers require a weak
12 volt pull-up for correct operation of the gauge. Tie the gray and white/red wires together if this is needed.
The tachometer is adjustable from 1 to 15 cylinder signals and calibration is discussed below. Diesel
engines will usually require a diesel tach adapter DSL-1 or DSL-2, available from Dakota Digital, Inc.
The gauge displays the engine rpmx10 from 250 – 9990 and rpmx1000 for 10,000 – 18,000. 2500 rpm
would be displayed as “250” and 11,400 rpm would be displayed as “11.4”. The decimal point indicates the reading
has changed from rpmx10 to rpmx1000.
The gauge can be set for a slow update, which changes the displayed reading every ½ second, or for a fast
update, which changes the displayed reading every 1/8 second. The slow update rate is recommended for most
applications since rapidly changing numbers can be difficult to read.
FUNCTION SWITCH/RECALL HIGH RPM
The function switch is connected with one wire to a 12 VDC source and the other wire connects to the green
wire from the tachometer harness. The function switch is used for calibration and to recall the highest rpm reached
since the last reset. Pressing the function switch while the gauge is running will display “HI” and then the current
high rpm. This will repeat every 2 seconds. Holding the function switch for 8 seconds will reset the high rpm.
The high rpm recall is updated every 1/8 second regardless of the display update rate. This allows it to
catch the highest rpm which might be missed at the slow update rate.
NIGHT DIMMING
Your display system has a dimming feature that reduces the display intensity. Normally the system is at full
brightness for daytime viewing. When the blue wire has 12 volts, the display intensity will be reduced. Connect this
to a park light or tail light circuit, then whenever the headlights are on the display will dim. To have the system at full
brightness all of the time, leave the blue wire disconnected.
