Installation Instructions

PRECAUTIONS:

* Read ALL instructions before installing instrument.
* Follow ALL safety precautions when working on vehicle-wear safety glasses!
* ALWAYS disconnect (-) negative battery cable before making electrical connections.

HELP?:
If after reading these instructions you do not fully understand how to install your instrument, contact USA Imports on 01530 450533 or email Neil and Jo

GENERAL APPLICATION:
12-volt DC negative (-) ground electrical systems (11-20 V DC operating voltage range for the tachometer, 11-16 V DC for the Light bulb).

TACHOMETER MOUNTING (Figures 1 & 2):

NOTE: Instructions apply to 3-3/8" & 5" Tachometer.

* Recommended panel cut-out (hole size) for 3-3/8" tachometer is 3-3/8".
* Recommended panel cut-out (hole size) for 5" tachometer is 4-5/8" if recessed to the bezel, or 3-3/8" if recessed to the step (Figure 1).
* Secure the tachometer in the hole using the supplied bracket for the 3-3/8" and the 5". Remove the 3 Torx screws using a T10 Torx driver. Insert the 3 studs and install lock washers and nuts to secure the rear cover. Install the bracket as shown in figure 2 and tighten the 3 locking nuts (5 in. Lb. max).
* When mounting on the dash or roll cage or steering column, use the cushioned strap & bracket as shown in figure 3.

TACHOMETER HOOK-UP (Figure 3):

!!!-NEVER CONNECT GREEN WIRE TO THE COIL WHEN USING AN MSD OR SIMILAR HIGH OUTPUT CAPACITIVE DISCHARGE STYLE IGNITION SYSTEM-!!!.

Damage to the tachometer will occur - Connect GREEN wire to the tachometer terminal only.

# Disconnect negative (-) battery cable.
# Using 18-ga. wire, connect the (BLACK) wire to a clean (rust/paint-free) ground, preferably battery negative terminal.
# Using 18-ga. wire, connect the (RED) wire to a switched +12V source, like the ignition wire.
# Using 18-ga. wire, connect the (GREEN) wire the coil negative or the tachometer terminal of the ignition module.
# There are two (2) wires for the lighting; Connect the (WHITE) lighting wire to the dash lighting circuit or to a +12V switched circuit. Connect the (BLACK) lighting wire to a chassis ground.
# Calibrate the pulses per revolution (PPR). Refer to the calibration set-up section.
# Reconnect the negative (-) battery cable & test instrument to ensure that it is working.

CALIBRATION (PPR/Number of Cylinders):
Until recently, tachometers were calibrated based on the number of cylinders in the engine. Now, there are all types of engine control modules (ECMs - on-board computers) and distributor-less ignitions and the old standard rule-"half the number of cylinders equals the pulses per revolution (PPR)"-no longer applies.
"Pulses per revolution" relates to how many times the ignition fires per crankshaft revolution. The tachometer outputs from the ECMs can range from 1-PPR to 4-PPR for a V-8 engine. So, the new standard is to refer to PPR instead of the number of cylinders.

SIGNAL INTERFACING:
Stewart Warner Performance tachometers are designed to work with a wide variety of ignition types, including standard inductive [coil (-) connection] and any ignition system with a clean tachometer output signal.
The input level can range from TTL 5V (outputs from newer engine control modules) and 300-400 volt pulses from coil (-) on most inductive ignition systems. Stewart Warner Performance tachometers will operate on most traditional capacitive discharge ignitions when connected to the ignition primary circuit. However, for high-output CD's (such as MSD) only connect to the tach output terminal, never the coil primary. It's best to consult our tech support hotline if you're unsure, rather than risk damage to the tachometer, ignition or your warranties.

CALIBRATION SET-UP (Figure 4):

NOTE: Stewart Warner Performance Tachometers come pre-set from the plant for a standard 8 cylinder 

(4 PPR) application. See "DIP-switch setting chart" for additional applications.

# Remove the 3 Torx screws using a T10 Torx driver.
# Refer to the "DIP-switch setting chart" to determine the settings for your application.
# Set the DIP-switches to the appropriate positions.
(see switch setting chart)

TIP: A small screw driver or pick may aide in the switch setting.
# Replace the rear cover and 3 Torx screws. 

Be sure that the rear sealing o-ring stays in place.

TROUBLESHOOTING:
Q: My tachometer does not respond at all, what do I do?
A: Check all of the wiring connections and power to the tachometer.

# If the tachometer needle goes to zero when powered up, but does not respond when the engine is started, there is no signal to the green wire. Check to ensure that the green wire is properly connected to a valid tach signal.
# If the tachometer needle does not go to zero when powered up, the tachometer is not grounded properly or does not have power to the (RED) wire. Check to ensure a good chassis ground, preferably at the battery ground. Verify that the (RED) wire has a 12VDC supply.

Q: My tachometer does not read correctly, what do I do?
A: First, determine how the reading is incorrect (example: Double, half, quarter etc.), then re-set the PPR calibration for correct readings.

# If the RPM reads double, re-set the PPR calibration for 1/2 of the current setting.
# If the RPM reads 1/2, re-set the PPR calibration for 2 times the current setting.
# If the RPM reads 1/4, re-set the PPR calibration for 4 times the current setting.

CLEANING DIRECTIONS:
For proper cleaning of instrumentation/accessories, use a glass cleaner or mild detergent with a spray on and wipe method.