Firstech, LLC. COMPUSTAR CM3000 - Manual (Page 5)

Firstech, LLC. Technical Data (CM3000)
5
Tachometer Sensing
1. You will need an Auto Ranging Digital Meter to test for the correct
tach.
2. Most tach wires are located at the (-) side of the ignition coil. In
some cases you may have to go to the ECU or Coil pack.
3. The Voltage will read (AC), so you will need to set you meter
accordingly.
4. With the vehicle off the voltage should read 0.00 AC.
5. Start the vehicle and at this time the voltage should fluctuate
between 1 and 8 volts AC.
6. Connect the tachometer wire to the yellow/black.
7. Make sure that the Dipswitch #1 is set to the On position.
8. While the vehicle is running press the small black button on the
side of the brain, the siren will chirp once if you have the correct
Tach wire.
9. If the cars parking lights flash 3 times, there is a problem with the
tachometer learning. Wait for 2 seconds and the cause for the
error will be indicated by the number of times the parking lights
flash.
Alternator Sensing
1. Just like with Tachometer sensing you will need a Auto Ranging
Digital Meter to test for the correct wire.
2. Set your meter to DC voltage for this type of sensing, compared to
AC voltage for the Tach sensing.
3. To find this wire you will need to locate the alternator. Look for the
Stator wire, which is always located somewhere on the alternator.
It will usually be a smaller gauge wire and generally by itself.
4. With the vehicle in the OFF position the voltage should read 0.00
5. Turn the key to Ignition and the voltage should read anywhere
from 1 to 6 volts DC
6. Next, start the vehicle. The voltage should now read between 9 to
14 volts DC.
7. If this is the case you have found the Alternator wire, connect this
to the Yellow/Black on CN 3
8. Set dipswitch #1 to the OFF position. Please note, you will not
need to press the small black button on the side of the brain, it is
automatic.