Floscan 5A20-20A-1 AccuTroll & CruiseMaster - Manual (Page 21)

08/20/2004 4001-102-00I
FloScan Instrument Company, Inc. Tel: (206) 524-6625 Fax: (206) 523-4961
3016 NE Blakeley Street, Seattle, WA 98105 Email: [email protected] Http://www.floscan.com
4. Move the voltmeters’ negative lead to the BROWN (Signal) wire. With engine idling, measure and record
the voltage reading. Readings between 4 and 10 VDC, usually indicate a good sensor. ___________VDC
5. Stop the engine and observe the voltmeter. Voltage readings should fluctuate between a high of 9 to 12
VDC, and a low of 0 to 4 VDC as the Sensors’ turbine slows to a stop.
NOTE: This may not be seen with a digital voltmeter.
6. The Sensor may be defective if voltage readings in steps 3 & 5 remain constant while the engine is
stopping.
7. On twin engine systems, try swapping the Brown & White signal wires. Observe the Instrument and see if the
problem shifts sides, or remains on the same side.
With this guide in hand, contact FloScan Technical Support.
III. BACKLIGHTING.
1. Referring to the wiring diagram, check back lighting bulb and Instrument illumination circuit.
IV. CHECK + 12 VDC and GROUND
1. Turn Instrument power ON, and go to the Instruments’ backside.
2. Measure between the RED (Power) wire and the BLACK (Instrument ground) wire.
__________VDC
This reading should be approximately 12 VDC, but not lower than 10 VDC.
3. If 12 VDC is not present, measure between the RED power wire and a known good ground in the
instrument panel. If you measure 12 to 14 VDC between the Red wire and ground, you may have __________VDC
an instrument ground problem.
4. If 12 to 14 VDC is not present in steps 2 or 3, check wiring, switches, fuse, and the 12 VDC power source.
V. CONTINUITY TESTING
1. Continuity testing requires access to the back of the Instrument and an Ohmmeter. It verifies that wires are not
broken, shorted to ground, another wire, or to power. Before starting, secure all power.
2. Disconnect the WHITE and BLACK wire harness conductors from the WHITE and BLACK Port Sensor
wires. Connect a jumper from the WHITE wiring harness conductor to a known good ground. At the ____________
back of the Instrument, connect an Ohmmeter lead to its’ WHITE wire. Connect the other Ohmmeter lead (Ohm Reading)
to a known, good ground. The Ohmmeter should read approximately 0.1 to 3
Ω.
3. Disconnect the BROWN and BLACK wire harness conductors from the WHITE and BLACK Starboard Sensor ____________
wires. Connect a jumper from the BROWN wiring harness conductor to a known good ground. At the back of the (Ohm Reading)
Instrument, connect an Ohmmeter lead to its’ BROWN wire. Connect the other Ohmmeter lead to a known good
ground. The Ohmmeter should read approximately 0.1 to 3
Ω.
VI. PULSATION PROBLEMS
A stiff anti-siphon valve, sticking carburetor float or miss-plumbed Pulsation Damper(s) can cause fluctuating GPH readings. These
are most pronounced at low Rpm’s and tend to disappear around mid throttle. They are annoying, but won’t affect totalizer accuracy.
To eliminate, repair or replace any defective parts, or re-plumb dampers according to the Fuel Flow Schematic Instructions.