Engine Electrical; Diagnostic Connector Location - Pontiac TRANS AM 1977 Service Manual

ENGINE ELECTRICAL 6D-1
SECTION 6 D
ENGINE ELECTRICAL
CONTENTS OF THIS SECTION
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Diagnostic Connector 6D-1
General Electrical System Diagnosis
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6D-5
Battery
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6D-7
Charging System
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6D-13
Ignition System
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6D-25
Cranking System
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6D-40
Specifications
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6D-47
DIAGNOSTIC
GENERAL DESCRIPTION
All 1977 Pontiac "B" series cars will be equipped with
an engine diagnostic connector, which is used to simplify
engine electrical system diagnosis. A second diagnostic
connector will be used if the vehicle is equipped with air
conditioning (see Section IB for further information on the
air conditioning connector). Figure 6D-1 illustrates the
location of the engine electrical connector. The connector
provides access to several test points within the starting,
charging, and ignition systems. Figure 6D-2 and 6D-3 show
the engine electrical diagnostic connector, diagnostic
procedures and the connector circuitry.
DIAGNOSIS
All of the tests listed below in coniunction with the
diagnostic connector can be performed using a voltmeter.
When a problem has been traced to a specific area (such as
faulty starter, HE1 unit, defective ignition switch, faulty
generator, undercharged battery, etc.) further reference to
Section 6D of the Service Manual may be required.
Some of the diagnostic connector terminal wires are
spliced into the unit feed wire, instead of going directly to the
connector on the unit. The connector at the unit should
always be checked before starting a repair. The splice can be
checked, if desired, by connecting a voltmeter to the
CONNECTOR
Fig.
6D-1
Diagnostic Connector Location
connector at the unit. Voltage should be the same as at the
terminal in the diagnostic connector. Refer to Fig. 6D-2 and
6D-3 for diagnostic procedures.