Document 3JqdpwQYQn8jbMvjxERKxDZox
CHAPTER 2/THE BATTERY, CHARGING, STARTING, AND LIGHTING SYSTEMS 12
Switches develop resistance as they age, caus Battery Cables
ing lamps to lose their brilliance. Wear in the
switch may cause an intermittent connection, which will result in flickering.
A fuse will usually burn out due to an over
6 & 12 VOLT BRAIDED TINNED COPPER BATTERY CABLE STRAPS
load, normally from a short circuit. Tail lights
and stop lights may use the same fuse as some
of the interior lights; so the driver will not be
5TH WHEEL GROUND
i H driving without rear lights without knowing
STRAP
something is wrong.
Wiring may develop loose or dirty connec
tions which result in the same types ofproblems that bad switches cause. Insulation may be worn off by rubbing and cause a short circuit. .1: Occasionally the socket may lose connection
12 VOLT UNIVERSAL NUT AND BOLT TERMINAL WITH 6" TRAILING LEAD
with the body of the vehicle, breaking contact with the ground.
6 & 12 VOLT INSULATED SWITCH TO STARTER
Late model cars have many accessories on
CABLES
board, which are all connected to the wiring cir
cuits. Any problem in an electrically powered
unit will have to be checkedfor power, correct wiring properfuse size, and ground path back
BATTERY JUMPER CABLES
to the battery.
Circuits can be checkedfor conductivity with
a test light, for resistance with an Ohmmeter, andfor voltage drop with a voltmeter. When
6 & 12 VOLT BONDING STRAP
you test primary wire leads or battery cables, do not remove them from the vehicle before test
(Figure 14) Battery cables.
ing; just touch one probe of the voltmeter or
The battery cables link the battery to the elec
volt/ohmmeter to each of the electrical compo trical systems of the vehicle. Because of the rela
nents to which the cable or lead is attached.
tively low voltage (pressure) and high amperage
(When checking a negative battery cable, for
(flow) needed to supply these electrical systems,
example, one probe should touch the negative
the battery cable is a large, stranded and jack
battery post and the other probe should touch
eted cable. Although some manufacturers use
the stud or bolt head used to secure the battery aluminum or copper-clad aluminum, most use
cable. When the engine is cranked and carrying all copper, which is an all-around superior con
its greatest electrical load, such as during start ductor for battery cables.
ing, the reading should not exceed 0.1 volt.) Wire should be clearly stripped approxi
In most cables, the copper is stranded and insulated for easy handling and for protection
mately 'As" longer than the length of the termi of the electrical system. Some vehicles, however,
!i nal's conductor clamp. Care should be taken not use a braided ground strap, generally tin-coated
to nick or cut any of the strands during strip
copper for corrosion resistance. Because of the
ping. When attaching the wire to the terminal, insert it until it "bottoms " in the clamp or
harsh environment battery cables exist in, the insulation is designed to withstand abrasion
approximately Vis" protrudes beyond the clamp. Make sure that no insulation is put into the clamp.
caused by vibration and to be resistant to attack by air and battery vapors.
Battery cable connections take many different
iE;
' 'ii
STARTING SYSTEM
forms, the most common of which is a lead
The automobile starting system includes both casting. This casting sometimes includes a trail
I); the battery cables and the starter motor.
ing lead used for grounding.