D 150 Pickup V8-318 5.2L (1984)
Volt Meter Gauge: Technical Service Bulletins
Voltmeter - Explanation for High Readings
Models
All 1984 Models Equipped With Magnetic Voltmeter Instrument Clusters
Subject
High Voltmeter Readings
Index
ELECTRICAL
Date
March 19, 1984-C
No.
08-11-84
P-982-C
SYMPTOM/CONDITION
The magnetic type of voltmeters used in subject 1984 vehicles are sensitive to heat build up inside the instrument cluster housing. The increased heat that
builds up places the voltmeter indicator toward the high end of the "normal" operating portion of the meter or, under the right conditions, may just enter
the "high warning" portion of the meter.
The conditions causing this high reading are as follows:
^
An hour or more of continuous driving at cold ambient temperatures (cold temperature operation causes the voltage regulator output to be higher
than hot temperature operation).
^
Instrument cluster illumination lamps and/or heater/defroster on, which increases temperatures around the voltmeter.
If a high voltmeter reading exists, verify battery and charging system are operating normally per service manual procedures. If system meets
specifications, assure customer that system is operating properly. Do not replace voltage regulator or voltmeter if test results meet service manual
specifications.
A defective voltage regulator (overcharging) will normally cause the voltmeter to read well into the warning area (full scale) and will occur immediately,
not over a period of an hour or more.
POLICY:
Information only