Chapter 7
1 / 65

Chapter 7 - PowerPoint PPT Presentation

  • Uploaded on

Chapter 7. Basic Troubleshooting and Repair Procedures. Overview. Tools Needed Circuit Troubleshooting Electrical Interference. Tools Needed. Multimeters Wiring Tools Miscellaneous Tools Do-It-Yourself Test Tools Commercial Testers. Multimeter.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about ' Chapter 7' - rogan-humphrey

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Chapter 7
Chapter 7

Basic Troubleshooting


Repair Procedures


  • Tools Needed

  • Circuit Troubleshooting

  • Electrical Interference

Tools needed
Tools Needed

  • Multimeters

  • Wiring Tools

  • Miscellaneous Tools

  • Do-It-Yourself Test Tools

  • Commercial Testers


  • Required features in a boat’s multimeter

    • Measure up to 50 VDC

      • DC voltages either 6, 12 and sometimes 24

    • Measure up to 250 VAC

      • AC voltages either 120 or 240

    • Measure resistance or continuity

      • Audible continuity checker is desirable

  • Desirable features

    • Measure AC and DC current up to 10 amps

    • Entry level measure current to approx. 250 mA

Analog multimeter
Analog Multimeter

  • Advantage - Low cost

  • Disadvantages

    • Difficult to read measurement value

    • Have to start at max value and work way down

Digital multimeter
Digital Multimeter

  • Advantages

    • Easy to read measurement value

    • More accurate readout

  • Disadvantages

    • Have to start at max value and work way down

    • Cost

Auto ranging multimeter
Auto-Ranging Multimeter

  • Advantage

    • Only have to select function (not range)

      • DC voltage, DC current, AC voltage or resistance

  • Disadvantage - cost

Wiring tools
Wiring Tools

  • Wire Cutter – Diagonal Cutter

    • 5 or 6” overall

    • Plastic cushion grip

  • Wire Stripper

    • Don’t use knife

    • Are dedicated tools

    • Most used – Combination Cut/Strip/Crimp Tool

      • Not to be used as crimp tool

      • Wire cutters at tip not effective

Wiring tools 2
Wiring Tools - 2

  • Ratcheting crimp tool required by ABYC

    • Covered in Chapter 2

    • Expensive compared to combination tool

  • Soldering gun

    • Normally boat wiring is NOT soldered

      • Done with crimp on terminals and butt spices

    • Required for some coax connectors

    • Recommend dual 100/140 watt

    • With appropriate tip will cut lines and fuse ends

Miscellaneous tools
Miscellaneous Tools

  • Pliers

    • To hold objects

      • Not a substitute for a wrench

    • Types

      • Slip joint

      • Needle nose

      • 5” or 6” overall with plastic cushioned grips

  • Wrench (for electrical work)

    • Adjustable 6”


  • Blade

    • 3/16” blade with 4” shaft

    • 1/4” blade with 4” shaft

  • Phillips

    • #1 with 4” shaft

    • #2 with 4” shaft

  • Small

    • 1/8” blade with approx. 2” shaft

    • #0 Phillips with approx. 2” shaft

Circuit trouble shooting
Circuit Trouble-Shooting

  • Batteries

  • Alternators

  • Battery Chargers

  • Boat Lighting System

  • Boat DC Electronic Systems

  • Boat AC Circuits

Battery testing
Battery Testing

  • Hydrometer

  • Open-Circuit Voltage

  • Load Test

  • Three-Minute Charge


  • Hydrometer – best tester of flooded-cell

    • Measures Specific Gravity

    • Chapter 3, Table 5

Open circuit voltage
Open-Circuit Voltage

  • For Maintenance Free, Gel & AGM batteries

    • When you can’t use a hydrometer

  • Battery should rest for 24 hours, or discharge with a large light bulb for a few minutes

  • Chapter 3, Table 5

Specific gravity voltages
Specific Gravity & Voltages

Specific Gravity (Flooded Cell @ 80 F)

Flooded Cell Voltage

Gelled Cell Voltage

AGM Voltage

Chapter 3 Table 3-5

Load test
Load Test

  • Hydrometer and open-circuit voltage do not indicate ability to provide current under load

  • Prevent engine from starting

    • Operate starter motor for approx 15 sec

    • Monitor battery voltage after 5 sec

  • If voltage is over 10.5 VDC – Good Battery

  • If voltage is under 10.5 VDC – Bad Battery

    • Replace battery

Three minute charge test
Three-Minute Charge Test

  • Actually takes six (6) minutes

  • Charge battery at 40A for six minutes

  • Measure voltage (at battery) with charger on

  • If voltage under 15.5 VDC – Battery is good

  • If voltage is over 15.5 VDC – Battery is bad

    • Not accepting charge

    • Is sulfated

    • Replace battery

Alternator testing
Alternator Testing

  • Drive Belt

  • Quick Test

  • Alternator Electrical Connections

Drive belt quick test
Drive Belt & Quick Test

  • Drive belt

    • Loose belt if “squealing” when engine started

    • Belt depression when pressed at midpoint

      • Normal (correct tightness) is only 3/8” to ½”

      • Over ½” is too loose, tighten belt

  • Quick test with engine & battery charger off

    • Measure (battery) voltage at alternator

    • Start engine and measure voltage at alternator

      • Alternator working if voltage increases

      • Alternator not working if voltage constant

Alternator electrical connections
Alternator Electrical Connections

To check wiring between alternator & battery

  • First discharge battery for five minutes

  • Then start engine & check for high resistance connection between alternator & battery

  • Voltage drop over 0.5 VDC needs to be fixed; or over 1.0 VDC if there are charging diodes

    • Check both positive and negative circuit

    • Clean and tighten the bad connection

    • If you find a bad wire, replace it

Battery charger testing
Battery Charger Testing

  • Alternator vs Battery Charger

  • Quick Test

  • Troubleshooting

Alternator vs charger quick test
Alternator vs Charger & Quick Test

  • Alternator vs Battery Charger

    • Batteries charged by alternator

    • Batteries not charged by battery charger

      • Defective battery charger; see Troubleshooting

  • Quick test with engine & charger off

    • Measure (battery) voltage at battery charger

    • Turn on battery charger and measure voltage

      • Battery charger working if voltage increases

      • Battery charger not working if voltage constant


  • If Charger not working, check the AC input

    • Troubleshoot like AC Circuit, covered later

  • If there is AC input, check for a blown fuse

    • Replace blown fuse ONCE

    • If fuse blows a 2nd time

      • Disconnect wire going to battery and install another fuse, then turn charger on

      • If fuse blows again, have defective charger

      • If fuse does NOT blow, measure DC voltage

        • Should be between 13 and 16 VDC

Troubleshooting 2
Troubleshooting - 2

  • Turn Charger “Off”

  • Disconnect charger positive wire at battery

    • Tape it to prevent wire shorting to ground

  • Reconnect positive wire at charger

  • Turn “On”, if fuse blows have short in wire

  • If fuse does not blow, may have high resistance connection between charger and battery

    • Troubleshoot wiring like you would for alternator

Boat lighting system
Boat Lighting System

  • Boat light inoperative

    • First replace bulb with known good bulb

    • Alternate test of suspect bulb

      • Check continuity of filament

        • Good bulb will have continuity or low resistance

        • Bad bulb will indicate no continuity or infinite resistance

    • If good bulb does not work

      • Need to troubleshoot lighting circuit

Lighting troubleshooting
Lighting Troubleshooting

  • Need a logical sequence

  • First check circuit breakers and switches

  • Then isolate to battery to power panel


  • Power panel to light

Chapter 7

Boat Light Inoperative

Replace / Check




Turn Battery

Switch On

Turn DC Main On








to Panel



Switch On






Battery to Panel



Main On






Panel to Light

Battery to power panel
Battery to Power Panel

No DC at battery side of DC main breaker

  • Check/replace large fuse at battery

    • Use multimeter

  • Check/clean/tighten wiring

    • Battery to battery fuse

    • Batter fuse to power panel

Power panel to light
Power Panel to Light

Have DC at load side of branch circuit breaker

  • Check/clean/tighten wiring at branch breaker

  • Check/clean corrosion at light socket

    • Use CRC QD Electronic Cleaner or equivalent

  • Check/replace in-line fuse near light

  • Check/replace switch in light

  • Check wiring with temporary wires from branch circuit breaker to light fixture

Boat dc electronic systems
Boat DC Electronic Systems

  • 90% of equipment problems is lack of DC

    or bad corroded cable connections

  • First check for power to equipment

    • If there is power

      • Check for blown fuse

      • If fuse is good, there is an equipment problem

  • Then check/clean cable connections

    • Use CRC QD Electronic Cleaneror equivalent

  • Lastly troubleshoot like a lighting system

    • Previously covered

Boat ac circuits
Boat AC Circuits

  • Testing

  • Troubleshooting

Testing ac circuits
Testing AC Circuits

  • Shore power polarity

    • Verify correct with Reverse Polarity Indicator

  • Outlets

    • When first installed and once a year

    • Verify with AC Outlet Tester

  • GFCI outlets

    • When first installed and once a year

    • Insert AC Outlet Tester

      • Press “Test” – tester lights should go “Off”

      • Press “Reset” – tester lights should go “On”

Testing hard wired appliances
Testing Hard Wired Appliances

  • Turn on appropriate branch circuit breaker


  • Appliance “On” switch

  • Appliance should work


  • Expose the AC terminal strip

    • Use multimeter

    • Check for AC voltage and polarity

  • If have AC input and won’t work = Defective

Troubleshooting ac circuits
Troubleshooting AC Circuits

  • Need logical sequence

  • First check circuit breakers and switches

  • Then isolate to dock to power panel


  • Power panel to outlet or appliance

Chapter 7




Reset Service Breaker


Main On


Turn AC Main On


Dock to Panel


Panel to

Outlet / Appliance

AC Troubleshooting



to Panel



Breaker Tripped








Dock to power panel
Dock to Power Panel

No AC at line side of AC main circuit breaker

  • Check/reset dockside circuit breaker

  • Check service cord

    • Use adapters and AC Outlet Tester

    • Power at dockside outlet?

    • Power at boat end of cable?

  • Check/clean/tighten connectors and wiring

    • Disconnect AC power before working on AC

    • Use CRC QD Electronic Cleaner on contacts

Power panel to outlet appliance
Power Panel to Outlet/Appliance

Have AC at load side of branch circuit breaker

  • Reset GFCI outlet

  • Disconnect AC power before working

  • Check/clean/tighten wiring at breaker

  • Check/clean/tighten wiring at


  • Check wiring with temporary wires from branch circuit breaker to outlet/appliance

Summary circuit troubleshooting
Summary – Circuit Troubleshooting


  • Battery tests: Voltage, Load and 3-minute charge

  • Alternator tests: Drive belt, quick test and wiring

  • Battery Charger: Quick test, AC power and wiring

  • Inoperative lights: Bulb, bulb contacts and wiring

  • DC electronics: Verify DC power & clean contacts

  • DC wiring: Start at power panel and isolate


  • Test outlets yearly

  • AC appliances: Verify AC power and check wiring

  • AC wiring: Start at power panel and isolate

Electrical interference
Electrical Interference

  • Introduction

  • Sources of Interference

  • Locating Interference Sources

  • Interference Suppression

  • Mitigation Techniques


  • Causes and Effects

    • Caused by rapid on/off current switching

    • Radiated through air

    • Conducted though wiring

    • Degrades high sensitivity electronic equipment

  • Noise Layers

    • Usually have interference from several sources

    • Remove/reduce till acceptable

    • Difficult to identify stronger interference

Sources of interference
Sources of Interference

  • Ignition Systems

  • Charging Systems

  • Voltage Regulators

  • Electric Motors

  • Gauges and Instruments

  • Propeller Shaft(s)

  • Video Displays

  • Electronic Equipment

  • Fluorescent Lights

Identification by sound
Identification by Sound

  • Ignition

    • Popping Sound related to engine speed

  • Alternator

    • High-pitched musical whine related to engine speed

  • Voltage Regulator

    • Intermittent rasping sound

  • Electric Motor

    • Hissing sound or whine

Locating sources
Locating Sources

  • What is Different?

  • What is On?

  • How is interference getting into equipment

    • Radiated?

    • Conductive?

  • Pigtail Check (with bypass capacitor)

  • Radio Noise “Sniffer”

Interference suppression
Interference Suppression

At source of interference

  • Approaches

    • Repair or replace faulty equipment

    • Shielding to confine interference

    • Special-purpose components to reduce interference

General suppression
General Suppression

  • Replace/repair faulty equipment

  • Correct defective wiring

    • Bonding straps still connected?

    • Check wiring for loose connections

  • Re-run wiring

    • Separate power and signal wires/cables

    • Dress regulator field wire close to the alternator

  • Shielding

    • Wires

    • Compartments with grounded copper screen

Ignition system
Ignition System

  • Primary

    • Shield ignition switch wiring

      • Ground shield at engine (only)

    • Ground case of ignition coil

    • Install 0.1 µf coaxial capacitor

      • in positive wire at coil

    • Install 0.005 µf disc ceramic capacitor

      • at negative terminal of coil

      • rated at 1,000 volts

    • Replace and adjust breaker points

    • Select and replace capacitor

Ignition system cont d
Ignition System – cont’d

  • Secondary

    • Install resistor spark plugs

  • Install resistor cable (between distributor and spark plugs)

  • Can be used together if needed


  • If output less than 50 Amps, add a 0.5 µf coaxial capacitor at output terminal

  • If over 50 Amps add a low-pass filter or in-line choke at the output terminal

  • Never bypass the alternator field

Charger voltage regulator
Charger / Voltage Regulator

Battery charger

  • Install near battery and away from electronics

  • Suppression built in by manufacturer

  • Home-made copper wire shield

    Voltage regulator

  • May be built in to alternator

  • If external

    • Mount close to alternator

    • Consider shielding field wire (ground both ends)

Electric motors
Electric Motors

  • Well seated brushes

  • By-pass with 0.25 to 0.5 µf capacitor

  • Ground housing

Gauges and instruments
Gauges and Instruments

Gauges and instruments

  • Bypass with 0.25 to 0.5 µf 200 volt capacitor

  • Some may stop working when bypassed

    Electric tachometers

  • Don’t bypass (it will stop working)

  • Shield wire and ground both ends

Propeller hash
Propeller Hash

  • Shaft Hash

  • Indicates stray current or galvanic current problem

    • If possible fix problem

  • Best to ground the shaft with carbon brushes

    • Fixes the symptom, not the problem

Electronic equipment
Electronic Equipment

  • All electronics and appliances should be FCC Type Approved

    • Part 15 B of the FCC Rules

    • Look for decal/label

  • Europe has a tougher RFI standard “CE”

    • Look for decal/label

Mitigation techniques
Mitigation Techniques

At equipment being interfered with

  • Approaches

    • Shielding against radiated interference

    • Filtering against conductive interference

  • Capacitors (or condensers)

  • Chokes (or inductors)

Shielding and capacitors
Shielding and Capacitors

  • Shielding for radiative interference

  • Capacitor (or condenser)

    • For conductive interference

    • Provide low reactance to AC

    • Placed across (parallel) input power terminals

    • Bypass undesirable AC noise to ground

Chokes inductors
Chokes (Inductors)

  • Choke (or inductor)

    • For conductive interference

    • Provides high reactance to AC

    • Placed in series with power wires

  • Types of RF chokes

    • In-Line

    • Snap-On

    • Ferrite Data-Line


  • Ground metal case

  • Bypass DC leads

  • Bypass and shunt DC leads

  • Add choke (in series with DC leads)

  • Shield (and ground shield)

Tv conductive interference
TV Conductive Interference

  • Turn AC outlet “Off”

  • Install 0.01 µF (micro farad) disc ceramic capacitor across hot and neutral terminals

    • Keep leads as short as possible

  • Install snap-on choke in power cord

    • 5 turns, left to right, on one side or core

    • Followed by 5 turns, left to right, on other side

Summary interference
Summary- Interference

  • Locating source

    • By its sound

    • What is different?

    • What is on?

    • By use of “sniffer”

  • Interference suppression (at source of interference)

    • Equipment repair

    • Specific at equipment

    • Shielding of equipment

Chapter 7

Summary– Interference - 2

  • New electronics and appliances should be FCC and/or CE Type Approved

  • Mitigation Techniques (at interfered-with equipment)

    • Shielding

    • Filtering