GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 128
•
Size - the larger the wire size being used, the less resistance the wire will
have. This is why components which use large amounts of electricity
usually have large wires suppl ying current to them.
• Length - for a given thickness of wire, the longer the wire, the greater the
resistance. The shorter the wire, the less the resistance. When
determining the proper wire for a circ uit, both size and length must be
considered to design a circuit that can handle the current needs of the
component.
• Temperature - with many materials, the higher the temperature, the
greater the resistance (positive temper ature coefficient). Some materials
exhibit the opposite trait of lower re sistance with higher temperatures
(negative temperature coefficient). Thes e principles are used in many of
the sensors on the engine.
OHM'S LAW
There is a direct relationship between current, voltage and resistance. The
relationship between current, voltage and resistance can be summed up by a
statement known as Ohm's law.
Voltage (E) is equal to amper age (I) times resistance (R): E=I x ROther forms of
the formula are R=E/I and I=E/R
In each of these formulas, E is the voltage in volts, I is the current in amps and
R is the resistance in ohms. The basic point to remember is that as the
resistance of a circuit goes up, the amount of current that flows in the circuit will
go down, if voltage remains the same.
The amount of work that the electricity can perform is expressed as power. The
unit of power is the watt (w). The re lationship between power, voltage and
current is expressed as:
Power (w) is equal to amperage (I) times voltage (E): W=I x EThis is only true
for direct current (DC) circuits; The alte rnating current formula is a tad different,
but since the electrical circuits in mo st vehicles are DC type, we need not get
into AC circuit theory.
ELECTRICAL COMPONENTS
POWER SOURCE
Power is supplied to the vehicle by tw o devices: The battery and the alternator.
The battery supplies electrical power dur ing starting or during periods when the
current demand of the vehicle's electrical system exceeds the output capacity of
the alternator. The alternator supplies electrical current when the engine is
running. Just not does the al ternator supply the current needs of the vehicle, but
it recharges the battery.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 129
THE BATTERY
In most modern vehicles, the battery is
a lead/acid electrochemical device
consisting of six 2 volt subs ections (cells) connected in se ries, so that the unit is
capable of producing approximately 12 volt s of electrical pressure. Each
subsection consists of a series of positive and negative plates held a short
distance apart in a solution of sulfuric acid and water.
The two types of plates are of dissim ilar metals. This sets up a chemical
reaction, and it is this r eaction which produces current flow from the battery
when its positive and negative terminals are connected to an electrical \
load .
The power removed from the battery is r eplaced by the alternator, restoring the
battery to its original chemical state.
THE ALTERNATOR
On some vehicles there isn't an alter nator, but a generator. The difference is
that an alternator supplies alternating current which is then changed to direct
current for use on the vehicle, while a generator produces direct current.
Alternators tend to be more efficient and that is why they are used.
Alternators and generators are devices t hat consist of coils of wires wound
together making big electrom agnets. One group of coils spins within another set
and the interaction of the magnetic fields causes a current to flow. This current
is then drawn off the coils and fed into the vehicles electrical system.
GROUND
Two types of grounds are used in automot ive electric circuits. Direct ground
components are grounded to the frame thr ough their mounting points. All other
components use some sort of ground wire which is attached to the frame or
chassis of the vehicle. The electrical current runs through the chassis of the
vehicle and returns to the battery thr ough the ground (—) cable; if you look,
you'll see that the battery ground cabl e connects between the battery and the
frame or chassis of the vehicle.
It should be noted that a good percentage of electrical problems can be traced
to bad grounds.
PROTECTIVE DEVICES
It is possible for large surges of current to pass through the electrical system of
your vehicle. If this surge of current we re to reach the load in the circuit, the
surge could burn it out or severely dam age it. It can also overload the wiring,
causing the harness to get hot and melt t he insulation. To prevent this, fuses,
circuit breakers and/or fusible links are connected into the supply wires of the
electrical system. These items are nothing more than a built-in weak spot in the
system. When an abnormal amount of curr ent flows through the system, these
protective devices work as fo llows to protect the circuit:
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 133
WIRING & HARNESSES
The average vehicle contains meters
and meters of wiring, with hundreds of
individual connections. To protect the many wires from damage and to keep
them from becoming a confusing tangl e, they are organized into bundles,
enclosed in plastic or taped together and called wiring harnesses. Different
harnesses serve different parts of the vehi cle. Individual wires are color coded
to help trace them through a harness wher e sections are hidden from view.
Automotive wiring or circuit conductors can be either single strand wire, multi-
strand wire or printed circui try. Single strand wire has a solid metal core and is
usually used inside such components as alternators, motors, relays and other
devices. Multi-strand wire has a core made of many small strands of wire
twisted together into a single conductor. Most of the wiring in an automotive
electrical system is made up of multi-strand wire, either as a single conductor or
grouped together in a harness. All wiring is color coded on the insulator, either
as a solid color or as a colored wire wit h an identification stripe. A printed circuit
is a thin film of copper or other conducto r that is printed on an insulator backing.
Occasionally, a printed circuit is sandwic hed between two sheets of plastic for
more protection and flexibility. A comp lete printed circuit, consisting of
conductors, insulating material and connec tors for lamps or other components
is called a printed circuit board. Printed ci rcuitry is used in place of individual
wires or harnesses in places where space is limit ed, such as behind instrument
panels.
Since automotive electrical systems are very sensitive to changes in resistance,
the selection of properly sized wires is critical when systems are repaired. A
loose or corroded connection or a replacem ent wire that is too small for the
circuit will add extra resistance and an addi tional voltage drop to the circuit.
The wire gauge number is an expression of the cross-section area of the
conductor. Vehicles from countries that use the metric system will typically
describe the wire size as its cross-secti onal area in square millimeters. In this
method, the larger the wire, the gr eater the number. Another common system
for expressing wire size is the Americ an Wire Gauge (AWG) system. As gauge
number increases, area decreases and the wire becomes smaller. An 18 gauge
wire is smaller than a 4 gauge wire. A wire with a higher gauge number will
carry less current than a wire with a lower gauge number. Gauge wire size
refers to the size of the strands of the conductor, not the size of the complete
wire with insulator. It is possi ble, therefore, to have two wires of the same gauge
with different diameters because one may hav e thicker insulation than the other.
It is essential to understand how a circuit works before trying to figure out why it
doesn't. An electrical schematic shows the electrical current paths when a
circuit is operating proper ly. Schematics break the enti re electrical system down
into individual circuits. In a schematic, usually no attempt is made to represent
wiring and components as they physically appear on the vehicle; switches and
other components are shown as simply as possible. Face views of harness
connectors show the cavity or terminal lo cations in all multi-pin connectors to
help locate test points.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 144
1. Isolate the circuit from
the vehicle's power source.
2. Ensure that the ignition key is OFF when disconnecting any components
or the battery.
3. Where necessary, also isolate at least one side of the circuit to be
checked, in order to avoid reading parallel resistances. Parallel circuit
resistances will always give a lower reading than the actual resistance of
either of the branches.
4. Connect the meter leads to both sides of the circuit (wire or component)
and read the actual measured ohms on the meter scale. Make sure the
selector switch is set to the proper ohm scale for the circuit being tested,
to avoid misreading the oh mmeter test value.
WIRE AND CONNECTOR REPAIR
Almost anyone can replace damaged wires, as long as the proper tools and
parts are available. Wire and terminals ar e available to fit almost any need.
Even the specialized weatherproof, mol ded and hard shell connectors are now
available from aftermarket suppliers.
Be sure the ends of all the wires are fitted with t he proper terminal hardware
and connectors. Wrapping a wire around a stud is never a permanent solution
and will only cause trouble later. Repl ace wires one at a time to avoid
confusion. Always route wires exac tly the same as the factory.
If connector repair is necessary, only atte mpt it if you have the proper tools.
Weatherproof and hard shell con nectors require special tools to release the pins
inside the connector. Attempting to r epair these connectors with conventional
hand tools will damage them.
BATTERY CABLES
DISCONNECTING THE CABLES
When working on any electrical component on the vehicle, it is always a good
idea to disconnect the negative (-) battery cable. This will prevent potential
damage to many sensitive electrical co mponents such as the Engine Control
Module (ECM), radio, alternator, etc.
Any time you disengage the battery cables, it is recommended that you
disconnect the negative (&mdash) battery cable first. This will prevent your
accidentally grounding the positive (+) term inal to the body of the vehicle when
disconnecting it, thereby prevent ing damage to the above mentioned
components.
Before you disconnect the cable(s), first turn the ignition to the OFF position.
This will prevent a draw on the battery which could cause arcing (electricity
trying to ground itself to the body of a vehi cle, just like a spark plug jumping the
gap) and, of course, damaging some com ponents such as the alternator diodes.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 223
FUSIBLE LINKS
In addition to circuit breakers and fuses,
the wiring harness incorporates fusible
links to protect the wiring. Links are used rather than a fuse, in wiring circuits
that are not normally fused, such as th e ignition circuit. The fusible links are
color coded red in the charging and load circuits to match the color coding of
the circuits they protect. Each link is four gauges smaller than the cable it
protects, and is marked on the insulation with the gauge size because the
insulation makes it appear heavier than it really is. The engine compartment
wiring harness has several fusible links. The same size wire with a special
Hypalon insulation must be used w hen replacing a fusible link.
For more details, see the information on fusible links at the beginning of this
section.
The links are located in the following areas:
1. A molded splice at the starter solenoid Bat terminal, a 14 gauge red wire.
2. A 16 gauge red fusible link at the j unction block to protect the unfused
wiring of 12 gauge or larger wire. This link stops at the bulkhead
connector.
3. The alternator warning light and fiel d circuitry is protected by a 20 gauge
red wire fusible link used in the batte ry feed-to-voltage regulator number
3 terminal. The link is installed as a molded splice in the circuit at the
junction block.
4. The ammeter circuit is protected by two 20 gauge fusible links installed
as molded splices in the circuit at t he junction block and battery to starter
circuit.
REPLACEMENT 1. Determine the circuit that is damaged.
2. Disconnect the negative battery terminal.
3. Cut the damaged fuse link from the harness and discard it.
4. Identify and procure the proper fuse link and butt connectors.
5. Strip the wire about
1/2 in. (13mm) on each end.
6. Connect the fusible link and crimp the butt connectors making sure that the wires are secure.
7. Solder each connection with resin core solder, and wrap the connections
with plastic electrical tape.
8. Reinstall the wir e in the harness.
9. Connect the negative battery terminal and test the system for proper
operation.
CIRCUIT BREAKERS
Various circuit breakers are located under the instrument panel. In order to gain
access to these components, it may be ne cessary to first remove the under
dash padding. Most of the circuit breakers are located in the convenience
center or the fuse panel.
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 344
ENGINE & ENGINE OVERHAUL
ENGINE ELECTRICAL
ENGINE ELECTRICAL
The engine electrical system can be brok en down into three inter-related, but
distinct systems:
1. The starting system.
2. The charging system.
3. The ignition system.
BATTERY AND STARTING SYSTEM
The battery is the first link in the chai n of mechanisms which work together to
provide cranking of the autom obile engine. In most modern cars, the battery is a
lead-acid electrochemical device consis ting of six two-volt (2V) subsections
connected in series so the unit is c apable of producing approximately 12V of
electrical pressure. Each subsection, or ce ll, consists of a series of positive and
negative plates held a short distance apart in a solution of sulfuric acid and
water. The two types of plates are of di ssimilar metals. This causes a chemical
reaction to be set up, and it is this reacti on which produces current flow from the
battery when its positive and negative te rminals are connected to an electrical
appliance such as a lamp or motor.
The continued transfer of electrons would ev entually convert the sulfuric acid in
the electrolyte to water and make t he two plates identical in chemical
composition. As electrical energy is removed from the battery, its voltage output
tends to drop. Thus, measuring batte ry voltage and battery electrolyte
composition are two ways of checking the ability of the unit to supply power.
During the starting of the eng ine, electrical energy is removed from the battery.
However, if the charging circuit is in good condition and the operating conditions
are normal, the power removed from the battery will be replaced by the
generator (or alternator) which will forc e electrons back through the battery,
reversing the normal flow, and restoring the ba ttery to its original chemical state.
The battery and starting motor are linked by very heavy electrical cable\
s
designed to minimize resistance to the flow of current. Generally, the major
power supply cable that leaves the batte ry goes directly to the starter, while
other electrical system needs are supplied by a smaller cable. During the starter
operation, power flows from the battery to the starter and is grounded through
the car's frame and the batte ry's negative ground strap.
The starting motor is a specially designed, direct current electric motor capable
of producing a very great am ount of power for its size. One thing that allows the
motor to produce a great deal of power is its tremendous rotating speed. It
drives the engine through a ti ny pinion gear (attached to the starter's armature),
which drives the very large flywheel ring gear at a greatly reduced speed.
Another factor allowing it to produce so much power is that only intermittent
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 346
battery, electricity is forced into the battery
, and the battery is returned to its fully
charged state.
Alternators are used on the modern autom obiles for they are lighter, more
efficient, can rotate at higher speeds and have fewer brush problems. In an
alternator, the field rotates while al l the current produced passes only through
the stators windings. The brushes bear agains t continuous slip rings rather than
a commutator. This causes the current produced to periodically reverse the
direction of its flow. Diodes (electrica l one-way switches) block the flow of
current from traveling in t he wrong direction. A series of diodes is wired together
to permit the alternating flow of the st ator to be converted to a pulsating, but
unidirectional flow at the alternator out put. The alternator's field is wired in
series with the voltage regulator.
Please refer to Engine Performance & Tune-up for ignition system testing
procedures.
IGNITION COIL
REMOVAL & INSTALLATION
INTERNALLY MOUNTED COIL 1. Disconnect and label the wires from cap.
2. Remove the distributor cap from the distributor.
3. On the distributor cap, remove t he coil cover attaching screws and the
cover.
4. Remove the ignition coil attaching screws and lift the coil from the cap.
To install: 5. Position the coil and secure it with the attaching screws. Be sure to install
the carbon button and rubber disc first.
6. Install the coil cover and attaching screws.
7. Install the distributor cap.
8. Connect the wires to the cap.
EXTERNALLY MOUNTED COIL 1. Label and disconnect the wires from the coil.
2. Remove the ignition coil mounting bolts and the coil.
To install: 3. To install, position the coil into place and se cure it with the mounting
bolts.
4. Connect the wires to the coil.
IGNITION MODULE
GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 350
4. Remove the distributor cover and wi
re retainer, if equipped. Turn the
retaining screws counterclockwise and remove the cap.
5. Mark the relationship of the roto r to the distributor housing and the
housing relationship to the engine.
6. Remove the distributor reta ining bolt and hold-down clamp.
7. Pull the distri butor up until the rotor just stops turning counterclockwise
and again note the position of the rotor.
8. Remove the distribut or from the engine.
To install: 9. Insert the distributor into the engine, with the rotor aligned to the last
mark made, then slowly install the dist ributor the rest of the way until all
marks previously made are aligned.
10. Install the distributor hold- down clamp and retaining bolt.
11. If removed, install the wiring harness retainer and secondary wires.
12. Install the distributor cap.
13. Engage the wire connections on t he distributor. Make certain the
connectors are fully seated and latched.
14. Reconnect the negative battery cable.
If the engine was accidentally cranked afte r the distributor was removed, the
following procedure can be used during installation.
15. Remove the No. 1 spark plug.
16. Place a finger over the spark pl ug hole. Have a helper turn the engine
slowly using a wrench on the crankshaft bolt until compression is felt. \
17. Align the timing mark on the pulley to 0 on the engine timing indicator.
18. Turn the rotor to point to the No . 1 spark plug tower on the distributor
cap.
19. Install the distributor assembly in the engine and ensure the rotor is
pointing toward the No. 1 spark plug tower.
20. Install the cap and spark plug wires.
21. Check and adjust engine timing.
ALTERNATOR
DESCRIPTION
An alternator differs from a DC shunt generator in that the armature is
stationary, and is called the stator, while the field rotates and is called the rotor.
The higher current values in the alternator's stator are conducted to the external
circuit through fixed leads and connecti ons, rather than through a rotating
commutator and brushes as in a DC generator. This eliminates a major point of
maintenance.
The rotor assembly is supported in the drive end frame by a ball bearing and at
the other end by a roller bearing. These bearings are lubricated during
assembly and require no main tenance. There are six diodes in the end frame
assembly. These diodes are electrical check valves that also change the