Mazda MX-5 1990 Workshop Manual page 749

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TROUBLESHOOTING GUIDE
Symptom
Blower motor does not operate
Magnetic clutch does not operate
Additional (condenser) fan does not operate
Insufficient cooling
No cooling
Intermittent cooling
9MUOUX-010
05UOTX-009
U-6
Reference page
U-7
U-9
U-11
U-12
ELECTRICAL TROUBLESHOOTING TOOLS
Jumper Wire
05UOUX-005
The jumper wire is used for testing by short-circuiting switch
terminals and to verify the condition of ground connections_
Caution
• Do not connect the jumper wire between a power
source and a body ground. Doing so may cause
burning or other damage to harnesses and electron-
ic components.
Voltmeter
The DC voltmeter is used for measurement of circuit voltage.
A voltmeter with a range of 15V or more must be used. It is
used by connecting the positive ( +) probe (red lead) to the
point where voltage is to be measured and connecting the
negative (-) probe (black lead) to a body ground.
Ohmmeter
The ohmmeter is used to measure the resistance between two
points in a circuit, to check for continuity, and to diagnose short
circuits.
Caution
• Never connect the ohmmeter to any circuit to which
voltage is applied. Doing so may burn or otherwise
damage the ohmmeter.
GENERAL PRECAUTION
Before Disconnecting BaJtery Cables
The optional audio unit has an anti-theft function that is acti-
vated when the battery power is disconnected. Obtain the code
number and deactivate the audio anti-theft system before dis-
connecting the battery. (Refer to page T
-113.)