Take Outs; Electrostatic Discharge Sensitive Devices; Troubleshooting Tools; Electrostatic Discharge Symbol - Jeep 200 Cherokee Service Manual

8W - 01 - 8
DESCRIPTION AND OPERATION (Continued)
WARNING: TO PREVENT SERIOUS BURNS, AVOID
CONTACT WITH HOT PARTS SUCH AS THE RADIA-
TOR, EXHAUST MANIFOLD(S), TAIL PIPE, CATA-
LYTIC CONVERTER, AND MUFFLER.
WARNING: DO NOT ALLOW FLAME OR SPARKS
NEAR THE BATTERY.
PRESENT IN AND AROUND THE BATTERY.
WARNING: ALWAYS REMOVE RINGS, WATCHES,
LOOSE HANGING JEWELRY, AND LOOSE CLOTH-
ING.

TAKE OUTS

The abbreviation T/O is used in the component
location section to indicate a point in which the wir-
ing harness branches out to a component.
ELECTROSTATIC DISCHARGE (ESD) SENSITIVE
DEVICES
All ESD sensitive components are solid state and a
symbol (Fig. 2) is used to indicate this. When han-
dling any component with this symbol comply with
the following procedures to reduce the possibility of
electrostatic charge build up on the body and inad-
vertent discharge into the component. If it is not
known whether the part is ESD sensitive, assume
that it is.
(1) Always touch a known good ground before han-
dling the part. This should be repeated while han-
dling the part and more frequently after sliding
across a seat, sitting down from a standing position,
or walking a distance.
(2) Avoid touching electrical terminals of the part,
unless instructed to do so by a written procedure.
(3) When using a voltmeter, be sure to connect the
ground lead first.
(4) Do not remove the part from its protective
packing until it is time to install the part.
(5) Before removing the part from its package,
ground the package to a known good ground on the
vehicle.
Fig. 2 Electrostatic Discharge Symbol
8W - 01 GENERAL INFORMATION
GASES ARE ALWAYS
DIAGNOSIS AND TESTING

TROUBLESHOOTING TOOLS

When diagnosing a problem in an electrical circuit
there are several common tools necessary. These tools
are listed and explained below.
• Jumper Wire - This is a test wire used to con-
nect two points of a circuit. It can be used to bypass
an open in a circuit.
WARNING: NEVER USE A JUMPER WIRE ACROSS
A LOAD, SUCH AS A MOTOR, CONNECTED
BETWEEN A BATTERY FEED AND GROUND.
• Voltmeter - Used to check for voltage on a cir-
cuit. Always connect the black lead to a known good
ground and the red lead to the positive side of the
circuit.
CAUTION: Most of the electrical components used
in today's vehicle are solid state. When checking
voltages in these circuits use a meter with a 10-me-
gohm or greater impedance rating.
• Ohmmeter - Used to check the resistance
between two points of a circuit. Low or no resistance
in a circuit means good continuity.
CAUTION: - Most of the electrical components used
in today's vehicle are Solid State. When checking
resistance in these circuits use a meter with a
10-megohm or greater impedance rating. In addi-
tion, make sure the power is disconnected from the
circuit. Circuits that are powered up by the vehicle
electrical system can cause damage to the equip-
ment and provide false readings.
• Probing Tools - These tools are used for probing
terminals in connectors (Fig. 3). Select the proper
size tool from Special Tool Package 6807, and insert
it into the terminal being tested. Use the other end
of the tool to insert the meter probe.
Fig. 3 Probing Tool
1 – SPECIAL TOOL 6801
2 – PROBING END
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