9/19/2003 7000-039-01
FloScan Instrument Company, Inc.
Tel: (206) 524-6625 Fax: (206) 523-4961
3016 NE Blakeley Street, Seattle, WA 98105 email: service@floscan.com http://www.floscan.com
ELECTRICAL
TwinScan Gas & Diesel Tachometer
Tachometer Wiring: For proper tachometer operation on Gasoline EFI engines, (especially outboards) the engine Ground wire must
be directly connected to the TwinScan Tachometer ground wire. FloScan recommends using dedicated 18 AWG shielded cable for
tachometer signal wire connections. Always, “Ground” wire shield or shield drain wire in the engine room by connecting it to the
bonding system, or engine block.
CARBURETOR & CLOSED LOOP EFI GASOLINE ENGINES with POINTS or STANDARD ELECTRONIC IGNITIONS
Inboard, & I/O Engines: Connect the Yellow tachometer signal wire to the negative terminal of the port engines’ distributor coil.
Connect the Violet tachometer signal wire to the negative terminal of the starboard engines’ distributor coil.
Outboard Engines: Outboard motor tachometers are connected to either the engine alternator or tachometer signal output wire.
Connect the Yellow tachometer signal wire the port engines’ alternator or tachometer signal output wire. Connect the Violet
tachometer signal wire to the starboard engines’ alternator or tachometer signal output wire.
CLOSED LOOP EFI GASOLINE ENGINES with CPU IGNITION SYSTEMS
Inboard, I/O, & Outboard Engines: Connect the Yellow tachometer signal wire to the port engines’ tachometer signal output wire.
Connect the Violet tachometer signal wire to the starboard engines’ tachometer signal output wire.
CHRYSLER (Except Magnapower I) - Connect tachometer signal wire(s) to the engine terminal strip marked, “ALT”.
JOHNSON/EVINRUDE/SEADRIVE - Connect tachometer signal wire(s) to the gray wire at key switch harness or Gray/Yellow
alternator wire on engine terminal strip. For 1984 and later model years with standard voltage regulators, connect the tachometer
signal wire(s) to either the Gray voltage regulator wire, or the Yellow/Gray alternator wire on the engine terminal strip.
MERCURY/MARINER - Attach tachometer signal wire(s) to the Yellow/Red, or Yellow wire terminal on engine rectifier.
SUZUKI - Remove three screws from rear of the throttle control box and remove cover plate. Attach tachometer signal wire(s) to the
Yellow wire, and shield ground wire to Black wire. Keep wires away from the moving parts in control box and reinstall back cover.
YAMAHA - Attach tachometer signal wire(s) to the Green wire, and shield ground wire to the Black wire at underside of shift control
box. If the Green wire is not accessible at control box, either Green wire on engine terminal strip can be used.
DIESEL ENGINES
New Installations: TwinScan Diesel Tachometers can use an Engine Alternator, Mechanically Driven AC Signal Generator, or a
Magnetic Pick-Up as the tachometer signal source.
•
Engine Alternator: Connect the Yellow tachometer signal wire to the port alternators’ tachometer output terminal (usually
marked “Tach” or “Sig”). Connect the Violet tachometer signal wire to the starboard alternators’ tachometer output terminal.
•
Mechanically Driven A-C Signal Generator, Magnetic Pickup: Signal Generators and Magnetic Pick-Ups have two terminals.
One terminal must be connected to battery minus or a ground buss. Connect the Yellow tachometer signal wire to the open
terminal on the port signal generator or magnetic pickup. Connect the VIOLET tachometer signal wire to the open terminal on the
starboard signal generator or magnetic pickup.
Keep or Replace Existing Tachometer: Connect the Yellow tachometer signal wire to the port tachometers signal output wire.
Connect the Violet tachometer signal wire to the starboard tachometers signal output wire. If using an AC Signal Generator or
Magnetic Pick-Up as the tachometer signal source, verify that one terminal is grounded.
FINAL ACTIONS
Check Electrical Installation: Test all connections. Support and secure all dangling wires to prevent accidental breakage. Proceed to
operate system and calibrate.
