
1-6 GENERALINFORMATIONAND MAINTENANCE 
Fig. 16 Screwdrivers should be kept in good 
:ondition to prevent injury or damage which 
:ould result it the blade slips from the screw 
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PP tccs1022 Fig. 16 Using the correct size wrench will 
help prevent the possibility of rounding off 
a nut 
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Fig. 17 Power tools should always be prop- 
erly grounded 
Fig. 19 NEVER work under a vehicle unless it 
is supported using safety stands (jackstands) 
l Do, when possible, pull on a wrench handle l Do set the parking brake and block the drive 
rather than push on it, and adjust your stance to pre- 
vent a fall. wheels if the work requires a running engine. 
l Do be sure that adjustable wrenches are 
tightly closed on the nut or bolt and pulled so that 
the force is on the side of the fixed jaw. 
l Do strike squarely with a hammer; avoid glanc- 
ing blows. l Don’t run the engine in a garage or anywhere 
else without proper ventilation-EVER! Carbon monoxide is poisonous; it takes a long time to leave 
the human body and you can build up a deadly sup- 
ply of it in your system by simply breathing in a !ittle 
every day. You may not realize you are slowly poi- 
soning yourself. Always use power vents, windows, 
fans and/or open the garage door. 
l Don’t work around moving parts while wearing 
loose clothing. Short sleeves are much safer than 
long, loose sleeves. Hard-toed shoes with neoprene 
soles protect your toes and give a better grip on slip- 
pery surfaces. Jewelry such as watches, fancy belt 
buckles, beads or body adornment of any kind is not 
safe working around a vehicle. Long hair should be 
tied back under a hat or cap. 
l Don’t use pockets for toolboxes. A fall or bump 
can drive a screwdriver deep into your body. Even a 
rag hanging from your back pocket can wrap around 
a spinning shaft or fan. 
l Don’t smoke when working around gasoline, 
cleaning solvent or other flammable material. 
l Don’t smoke when workrng around the battery. 
When the battery is being charged, it gives off explo- 
sive hydrogen gas. 
l Don’t use gasoline to wash your hands; there 
are excellent soaps available. Gasoline contains dan- 
gerous additives which can enter the body through a 
cut or through your pores. Gasoline also removes all 
the natural oils from the skin so that bone dry hands 
will suck up oil and grease. 
l Don’t service the air conditioning system un- 
less you are equipped with the necessary tools and 
trainmg. When liquid or compressed gas refrigerant 
is released to atmospheric pressure it will absorb 
heat from whatever it contacts. This will chill or freeze 
anything it touches. 
l Don’t use screwdrivers for anything other than 
driving screws! A screwdriver used as an prying tool 
can snap when you least expect it, causing injuries. 
At the very least, you’ll ruin a good screwdriver. 
. Don’t use an emergency jack (that little ratchet, 
scissors, or pantograph jack supplied with the vehi- 
cle) for anything other than changing a flat! These 
jacks are only Intended for emergency use out on the 
road; they are NOT designed as a maintenance tool. If 
you are serious about mamtaining your vehicle your- 
self, invest in a hydraulic floor jack of at least a 1% 
ton capacity, and at least two sturdy jackstands. 
sion which can increase the torque necessary to proper installation and safe operation of the vehicle 
achieve the desired clamp load for which that fastener afterwards. 
was originally selected. Additionally, be sure that the Thread gauges are available to help measure a bolt 
p See Figures 20, 21, 22, and 23 driver surface of the fastener has not been compro- or stud’s thread. Most automotive and hardware 
mised by rounding or other damage. In some cases a stores keep gauges available to help you select the 
Although there are a great variety of fasteners found driver surface may become only partially rounded, al- proper size. In a pinch, you can use another nut or 
in the modern car or truck, the most commonly used lowing the driver to catch in only one direction. In bolt for a thread gauge. If the bolt you are replacing is 
retainer is the threaded fastener (nuts, bolts, screws, many of these occurrences, a fastener may be in- not too badly damaged, you can select a match by 
studs, etc.). Most threaded retainers may be reused, stalled and tightened, but the driver would not be able finding another bolt which will thread in its place. If 
provided that they are not damaged in use or during to grip and loosen the fastener again. (This could lead you find a nut which threads properly onto the dam- 
the repair. Some retainers (such as stretch bolts or J to frustration down the line should that component aged bolt, then use that nut to help select the replace- 
torque prevailing nuts) are designed to deform when ever need to be disassembled again). ment bolt If however, the bolt you are replacing is so 
tightened or in use and should not be reinstalled. If you must replace a fastener, whether due to de- badly damaged (broken or drilled out) that its threads 
Whenever possible, we will note any special re- sign or damage, you must ALWAYS be sure to use cannot be used as a gauge, you might start by look- 
tainers which should be replaced during a procedure. the proper replacement In all cases, a retainer of the ing for another bolt (from the same assembly or a 
But you should always inspect the condition of a re- same design, material and strength should be used. similar location on your vehicle) which will thread 
tainer when It is removed and replace any that show Markings on the heads of most bolts will help deter- into the damaged bolt’s mounting. If so, the other bolt 
signs of damage. Check all threads for rust or corro- mine the proper strength of the fastener. The same 
can be used to select a nut; the nut can then be used 
material, thread and pitch must be selected to assure 
to select the replacement bolt.  

6-2 CHASSIS ELECTRICAL 
) See Figure 1 
For any 12 volt, negative ground, electrical system 
to operate, the electricity must travel in a complete 
circurt. This simply means that current (power) from 
the posibve (t) terminal of the battery must eventu- 
ally return to the negative (-) terminal of the battery. 
Along the way, this current will travel through wires, 
fuses, switches and components. If, for any reason, 
the flow of current through the circuit is interrupted, 
the component fed by that circuit will cease to func- 
tion properly. 
Perhaps the easiest way to visualize a circuit is to 
think of connecting a light bulb (with two wires at- 
tached to it) to the battery-one wire attached to the 
negative (-) terminal of the battery and the other wire 
to the positive (t) terminal. With the two wires touch- 
ing the battery terminals, the circuit would be com- 
plete and the light bulb would illummate. Electricity 
would follow a path from the battery to the bulb and 
back to the battery. It’s easy to see that wrth longer 
wires on our light bulb, it could be mounted any- 
where. Further, one wire could be fitted with a switch 
so that the light could be turned on and off. 
The normal automotive circuit differs from this 
simple example in two ways, Frrst, instead of having 
a return wire from the bulb to the battery, the current 
travels through the frame of the vehicle. Since the 
negative (-) battery cable is attached to the frame 
(made of electrically conductive metal), the frame of 
the vehicle can serve as a ground wire to complete 
the circuit. Secondly, most automotive circuits con- 
tain multiple components which receive power from a 
single circuit. This lessens the amount of wire 
needed to power components on the vehicle. 
HOW DOES ELECTRlClTYWORK:THE 
WATER ANALOGY 
Electricity is the flow of electrons-the subatomic 
particles that constitute the outer shell of an atom. 
Electrons spin in an orbit around the center core of 
RETURN 
RETURN 
CONDUCTOR 
CONDUCTOR 
GROUND 
GROUND 
lccs2w 
Fig. 1 This example illustrates a simple cir- 
cuit. When the switch is closed, power from 
the positive (t) battery terminal flows 
through the fuse and the switch, and then 
to the light bulb. The light illuminates and 
the circuit is completed through the ground 
wire back to the negative (-) battery termi- 
nal. In reality, the two ground points shown 
in the illustration are attached to the metal 
frame of the vehicle, which completes the 
circuit back to the battery 
an atom The center core is comprised of protons 
(positive charge) and neutrons (neutral charge). Elec- 
trons have a negative charge and balance 
out the 
positive charge of the protons. When an outside force 
causes the number of electrons to unbalance the 
charge of the protons, the electrons will split off the 
atom and look for another atom to balance out. If this 
imbalance is kept up, electrons will continue to move 
and an electrical flow will exist. 
Many people have been taught electrical theory 
using an analogy with water. In a comparison wrth 
water flowing through a pipe, the electrons would be 
the water and the wire is the pipe. 
The flow of electricity can be measured much like 
the flow of water through a pipe. The unit of measure- 
ment used is amperes, frequently abbreviated as 
amps (a). You can compare amperage to the volume 
of water flowing through a pipe. When connected to a 
circuit, an ammeter WIII measure the actual amount of 
current flowing through the circuit. When relatively 
few electrons flow through a circuit, the amperage is 
low. When many electrons flow, the amperage is 
high. 
Water pressure is measured in units such as 
pounds per square inch (psi); The electrical pressure 
is measured in unrts called volts (v). When a volt- 
meter is connected to a circuit, it is measuring the 
electrical pressure. 
The actual flow of electricity depends not only on 
voltage and amperage, but also on the resistance of 
the circuit The higher the resistance, the higher the 
force necessary to push the current through the cir- 
cuit. The standard unit for measuring resistance is an 
ohm. Resistance in a crrcuit varies dependmg on the 
amount and type of components used in the circuit. 
The main factors which determine resistance are: 
l Material-some materials have more resis- 
tance than others Those with high resistance are said 
to be insulators Rubber materials (or rubber-like 
plashcs) are some of the most common insulators 
used in vehicles as they have a very high resistance 
to electricity Very low resistance materials are said to 
be conductors. Copper wire is among the best con- 
ductors. Silver is actually a superior conductor to 
copper and is used in some relay contacts, but its 
high cost prohibits its use as common wiring Most 
automotive wiring is made of copper. 
l Size-the larger the wire size being used, the 
less resistance the wire will have. This IS why com- 
ponents which use large amounts of electricity usu- 
ally have large wires supplying current to them. 
l Length-for a given thickness of wire, the 
longer the wire, the greater the resistance. The 
shorter the wire, the less the resistance. When deter- 
mining the proper wire for a circuit, both size and 
length must be considered to design a circuit that can 
handle the current needs of the component. 
l Temperature-with many materials, the higher 
the temperature, the greater the resistance (positive 
temperature coefficient). Some materials exhibit the 
opposite trait of lower resistance with higher temper- 
atures (negative temperature coefficient). These prin- 
ciples 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 cur- rent, voltage and resistance can be summed up by a 
statement known as Ohm’s law. 
Voltage (E) is equal to amperage (I) times resis- 
tance (R): E=l x R 
Other 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 re- 
sistance of a circuit goes up, the amount of current 
that flows in the circuit will go down, if voltage re- 
mains the same. 
The amount of work that the electricity can perform 
is expressed as power. The unit of power is the watt 
(w). The relationship between power, voltage and 
current 
IS expressed as: 
Power(w) is equal to amperage (I) times voltage 
(E): W=l x E 
This is only true for direct current (DC) circuits: 
The alternating current formula is a tad different, but 
since the electrical circuits in most vehicles are DC 
type, we need not get into AC circuit theory. 
POWERSOURCE 
Power is supplied to the vehicle by two devices: 
The battery and the alternator. The battery supplies 
electrical power during 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 alternator supply 
the current needs of the vehicle, but it recharges the 
battery. 
The Battery 
In most modern vehicles, the battery is a lead/acid 
electrochemical device consisting of six 2 volt sub- 
sections (cells) connected in series, so that the unit 
is capable of producing approximately 12 volts of 
electrical pressure. Each subsection consists of a se- 
ries of positive and negative plates held a short dis- 
tance apart in a solutron of sulfuric acid and water. 
The two types of plates are of dissimilar metals, 
This sets up a chemrcal reaction, and it is this reac- 
tion which produces current flow from the battery 
when Its positive and negattve terminals are con- 
nected to an electrical load. The power removed from 
the battery is replaced by the alternator, restoring the 
battery to its original chemical state. 
The Alternator 
On some vehicles there isn’t an alternator, but a 
generator. The difference IS that an alternator sup- 
plies alternating current which is then changed to di- 
rect 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 that consist 
of coils of wires wound together making big electro- 
magnets. 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.  

6-30 CHASSIS ELECTRICAL 
1992-96 Diamante fuse location chart 
I 
Fuse load caaacities 15 -2OA Horn 
16 - 20A (E.C.S.) 
1 - 15A Cigarette lighter 17 - spare fuse 
2 - 10A Radio 
3 - 10A Heater relay, (Power window ( ) indicates optlonal equipment 
relay) E P.S.: Electronic Control Power Steer- 
4 - 10A (E.P.S) ing 
5 - 10A Turn signals, SRS E.C.S.: Electronic Control Suspension 
6 - 10A Meters, SRS SRS~ Supplement Restratnt System 
7 - 15A Wiper A/T: Automatic Transaxle 
8-10A (4AIT) 
9- 15A Steering handle lock, (Door 
locks) 
lo- 10A Dome light, Clock 
11 - 10A Backup lights 
12 -2OA StoplIghts 
13 -3OA Heater 
14 - 20A (Sunroof) 
93156fllE 
1997-00 Diamante passenger compartment fuse location chart No Symbol Electrical System 
I capactty 
I 
Spare fuses are contained in the fuse housing 
use a fuse of the same capacity for replacement. 
199740 Diamante encline 
compartment fuse location chart  

11-8 TROUBLESHOOTING 
Ignition systems may be controlled by, or linked to, the engine fuel management sys- 
tem. Similar to the fuel injection system, these ignition systems rely on electronic sen- 
sors for information to determine the optimum ignition timing for a given engine speed 
and load. Some ignition systems no longer allow the ignition timing to be adjusted. 
Feedback from low voltage electrical sensors provide information to the control unit to 
determine the amount of ignition advance. On these systems, if a failure occurs the failed 
component must be replaced. Before replacing suspected failed electrical components, 
carefully inspect the wiring and electrical connectors to the related components. Make 
sure the electrical connectors are fully connected, clean and not physically damaged. If 
necessary, clean the electrical contacts using electrical contact cleaner. The use of clean- 
ing agents not specifically designed for electrical contacts should be avoided, as they 
could leave a surface film or damage the insulation of the wiring. 
1. Engine makes a knocking or pinging noise when accelerating 
a. Check the octane rating of the fuel being used. Depending on the type of driving or 
driving conditions, it may be necessary to use a higher octane fuel. 
b. Verify the ignition system settings and operation. Improperly adjusted ignition timing 
or a failed component, such as a knock sensor, may cause the ignition timing to ad- 
vance excessively or prematurely. Check the ignition system operation and adjust, or 
replace components as needed. 
c. Check the spark plug gap, heat range and condition. If the vehicle is operated in se- 
vere operating conditions or at continuous high speeds, use a colder heat range spark 
plug. Adjust the spark plug gap to the manufacturer’s recommended specification and 
replace worn or damaged spark plugs. 
2. Sfarter motor grinds when used 
a. Examine the starter pinion gear and the engine ring gear for damage, and replace dam- 
aged parts. 
b. Check the starter mounting bolts and housing. If the housing is cracked or damaged 
replace the starter motor and check the mounting bolts for tightness. 
3. Engine makes a screeching noise 
a. Check the accessory drive belts for looseness and adjust as necessary. 
b. Check the accessory drive belt tensioners for seizing or excessive bearing noises and 
replace if loose, binding, or excessively noisy. 
c. Check for a seizing water pump. The pump may not be leaking; however, the bearing 
may be faulty or the impeller loose and jammed. Replace the water pump. 
4. Engine makes a growling noise 
a. Check for a loose or failing water pump. Replace the pump and engine coolant. 
b. Check the accessory drive belt tensioners for excessive bearing noises and replace if 
loose or excessively noisy. 
5. Engine makes a ticking or tapping noise 
a. On vehicles with hydraulic lash adjusters, check for low or dirty engine oil and top off 
or replace the engine oil and filter. 
b. On vehicles with hydraulic lash adjusters, check for collapsed lifters and replace failed 
components. 
c. On vehicles with hydraulic lash adjusters, check for low oil pressure caused by a re- 
stricted oil filter, worn engine oil pump, or oil pressure relief valve. 
d. On vehicles with manually adjusted valves, check for excessive valve clearance or 
worn valve train parts. Adjust the valves to specification or replace worn and defective 
parts. 
e. Check for a loose or improperly tensioned timing belt or timing chain and adjust or re- 
place parts as necessary. 
f. Check for a bent or sticking exhaust or intake valve. Remove the engine cylinder head 
to access and replace. 
6. Engine makes a heavy knocking noise 
a. Check for a loose crankshaft pulley or flywheel; replace and torque the mounting 
bolt(s) to specification. 
b. Check for a bent connecting rod caused by a hydro-lock condition. Engine disassem- 
bly is necessary to inspect for damaged and needed replacement parts. 
c. Check for excessive engine rod bearing wear or damage. This condition is also asso- 
ciated with low engine oil pressure and will require engine disassembly to inspect for 
damaged and needed replacement parts, 
7. Vehicle has a fuel odor when driven ’ a. Check the fuel gauge level. If the fuel gauge registers full, it is possible that the odor is 
caused by being filled beyond capacity, or some spillage occurred during refueling. 
The odor should clear after driving an hour, or twenty miles, allowing the vapor canis- 
ter to purge. 
b. Check the fuel filler cap for looseness or seepage. Check the cap tightness and, if 
loose, properly secure. If seepage is noted, replace the filler cap. 
c. Check for loose hose clamps, cracked or damaged fuel delivery and return lines, or 
leaking components or seals, and replace or repair as necessary. d. Check the vehicle’s fuel economy. If fuel consumption has increased due to a failed 
component, or if the fuel is not properly ignited due to an ignition related failure, the 
catalytic converter may become contaminated. This condition may also trigger the 
check engine warning light. Check the spark plugs for a dark, rich condition or verify 
the condition by testing the vehicle’s emissions. Replace fuel fouled spark plugs, and 
test and replace failed components as necessary. 
5. Vehicle has a rotten egg odor when driven 
a. Check for a leaking intake gasket or vacuum leak causing a lean running condition. A 
lean mixture may result in increased exhaust temperatures, causing the catalytic con- 
verter to run hotter than normal. This condition may also trigger the check engine 
warning light. Check and repair the vacuum leaks as necessary. 
b. Check the vehicle’s alternator and battery condition. If the alternator is overcharging, 
the battery electrolyte can be boiled from the battery, and the battery casing may begin 
to crack, swell or bulge, damaging or shorting the battery internally. If this has oc- 
curred, neutralize the battery mounting area with a suitable baking soda and water 
mixture or equivalent, and replace the alternator or voltage regulator. Inspect, service, 
and load test the battery, and replace if necessary. 
9. Vehicle has a sweet odor when driven 
a. Check for an engine coolant leak caused by a seeping radiator cap, loose hose clamp, 
weeping cooling system seal, gasket or cooling system hose and replace or repair as 
needed. 
b. Check for a coolant leak from the radiator, coolant reservoir, heater control valve or 
under the dashboard from the heater core, and replace the failed part as necessary. 
c. Check the engine’s exhaust for white smoke in addition to a sweet odor. The presence 
of white, steamy smoke with a sweet odor indicates coolant leaking into the combus- 
tion chamber. Possible causes include a failed head gasket, cracked engine block or 
cylinder head. Other symptoms of this condition include a white paste build-up on the 
inside of the oil filler cap, and softened, deformed or bulging radiator hoses. 
19. Engine vibraies when idling 
a. Check for loose, collapsed, or damaged engine or transmission mounts and repair or 
replace as necessary. 
b. Check for loose or damaged engine covers or shields and secure or replace as neces- 
sary. 
11. Engine vibrates during acceleration 
a. Check for missing, loose or damaged exhaust system hangers and mounts; replace or 
repair as necessary. 
b. Check the exhaust system routing and fit for adequate clearance or potential rubbing; 
repair or adjust as necessary. 
7. Battery goes dead while driving 
a. Check the battery condition. Replace the battery if the battery will not hold a charge or 
fails a battery load test. If the battery loses fluid while driving, check for an overcharg- 
ing condition. If the alternator is overcharging, replace the alternator or voltage regula- 
tor. (A voltage regulator is typically built into the alternator, necessitating alternator re- 
placement or overhaul.) 
b. Check the battery cable condition. Clean or replace corroded cables and clean the bat- 
tery terminals. 
c. Check the alternator and voltage regulator operation. If the charging system is over or 
undercharging, replace the alternator or voltage regulator, or both. 
d. Inspect the wiring and wire connectors at the alternator for looseness, a missing . 
ground or defective terminal, and repair as necessary. 
e. Inspect the alternator drive belt tension, tensioners and condition. Properly tension the 
drive belt, replace weak or broken tensioners, and replace the drive belt if worn or 
cracked. 
2. Battery goes dead overnight 
a. Check the battery condition. Replace the battery if the battery will not hold a charge or 
fails a battery load test. 
b. Check for a voltage draw, such as a trunk light, interior light or glove box light staying 
on. Check light switch position and operation, and replace if defective. 
c. Check the alternator for an internally failed diode, and replace the alternator if defec- 
tive. 
1. Engine overheats 
a. Check the coolant level. Set the heater temperature to full hot and check for internal air 
pockets, bleed the cooling system and inspect for leakage. Top off the cooling system 
with the correct coolant mixture. 
b. Pressure test the cooling system and radiator cap for leaks. Check for seepage caused 
by loose hose clamps, failed coolant hoses, and cooling system components such as 
the heater control valve, heater core, radiator, radiator cap, and water pump. Replace 
defective parts and fill the cooling system with the recommended coolant mixture.