Owner's manual
Digital Series Tachometer 
For Product Numbers: GS-BD10 and GS-RD10 
Wire Color Code 
Red: 
12v Ignition Source (+) (switched) 
Orange: 
12v Switched Headlamp Source (+) (optional) 
Black: 
Vehicle Ground ( - ) 
Green: 
Connects to Vehicle’s Tachometer Source 
1. Disconnect the negative battery cable. 
Connecting the Power Wire Harness 
2.  Connect  the  green  wire  to  the  vehicle’s  tachometer  source  wire  or 
negative side of the coil. You must consult your manual to ensure proper 
location.  If connecting  to  an  aftermarket  ignition  system, be  sure  to 
follow  the  manufacturer’s  instructions  for  connecting  a  tachometer. 
Please consult a service manual or mechanic before installing. 
  Tachometer Test Wire: Some vehicles may have a tachometer 
test wire to obtain a tachometer signal from. Consult your repair 
manual  or licensed  mechanic  to  confirm  the location  of  this 
wire. 
  Tachometer  Adapter:  It  may  be  necessary  to  install  a 
Tachometer  Adapter  if  you  have  a  multiple  coil  system.  You 
can purchase a Tachometer Adapter from local auto parts store. 
  Tachometer Filter: It may be necessary to use a Tachometer 
Filter  if  you  vehicle  has  either  a  points  style  or  HEI  ignition 
system.  You  can  purchase  a  Tachometer  Filter  from 
www.GlowShift.com 
  Note: Be sure to use a grommet when routing wires through 
the firewall to protect them from stripping and damage. 
3. Using automotive grade wiring (18 gauge); connect the red wire to a 
positive 12 volt ignition (switched) source. It  may be connected to the 
fuse panel, an accessory wire, or any positive 12 volt source that turns on 
and off with the ignition. 
4. Using automotive grade wiring (18 gauge); connect the black wire to 
any good (unpainted) ground connection. You may  also route a  wire 
directly to the negative side of the vehicle’s battery.  
5. The Night Time Dimming  feature  decreases  the brightness of the  gauge 
face  by  30%.  Connect  the orange  wire  to  the  12 volt  positive  headlamp 
source.  This allows the  mode to  be  activated  when the  headlights come  on. 
This step is optional and will not affect operation of the gauge if it is omitted. 
  Note: Do not connect the orange wire to a dimmer wheel. This will 
cause the gauge lighting to flicker. 
6.  Use  the  Cylinder  Selection  Switch  on the  back of  the  gauge to  set the 
number of engine cylinders on the tachometer to match that of your vehicle. 
Do this before applying power to the gauge.  
  If you need to change the cylinder selection, you must remove power 
from the gauge, make your selection, and then reapply power to the 
gauge for proper calibration. 
Switch # 
Cylinders 
0 
10 
1 
1 
2 
2 
3 
3 
4 
4 
5 
5 
6 
6 
7 
7 
8 
8 
9 
9 
7. Reconnect the negative battery cable. 



