Manual

ISSPRO, INC. 2515 N.E. Riverside Way, Portland OR 97211
Telephone: [phone]  Toll Free: [phone]
FAX: [phone]
Form # IS133 (6/2/99)
ISSPRO 3 3/8" DIA. ALTERNATOR TACHOMETER
GENERAL INFORMATION:
OPERATING VOLTAGE: 11-30 VDC: NOTE: Instrument comes equipped with a 12V lamp.
Replace lamp with part number 656 when installing instrument on 24V systems.
INPUT SIGNAL: Alternator Tap
TRANSIENT PROTECTION: +100 V, -400 V
REVERSE VOLTAGE PROTECTED
HOUR METER (optional) operates only when engine runs
CALIBRATION RANGE:
Calibration of the alternator tachometer requires that the alternator poles and pulley ratio's be within the
ratio's in the following chart:
NUMBER OF ALTERNATOR FIELD POLES PULLEY RATIO
8 2.6 to 5.4
12 1.7 to 3.6
14 1.5 to 3.1
16 1.3 to 2.7
CALIBRATION: (To be done before installation into dash.)
Remove the hole plug by pressing above the center enough to allow a small coin, screwdriver, etc. to be
inserted in the slot behind the upper edge. Twist to remove. It is necessary to run the engine at a known
RPM determined by either a "Master Tach" or an instrument such as ISSPRO's R1620C Digital Photo Tach.
While running the engine at the known RPM, adjust the calibration pot until the meter reads correctly.
Reinstall the hole plug.
INSTALLATION:
Mount the tachometer in the dash panel
and connect the wires as described below:
Make all of your connections to the Black plug supplied
and then plug it into the tachometer's white connector.
RED - Connect to ignition switched power source
BLACK - Connect to ground
WHITE - Connect to Alternator Tap (Stator)
GREEN - Connect to dash lamp power
TROUBLESHOOTING:
1.) When power is applied, the needle should go to the zero position. If it doesn't there may be a bad
connection in the "hot" (red wire) or ground wire circuit. Check power to the meter by measuring with a
voltmeter at the plug (meter leads on the pins that attach to the red and black wires.) If there is power at
the plug, the problem is in the gauge.