Chevrolet Corvette 1963 Repair & Tune-Up Manual page 88

82 ENGINE AND ENGINE REBUILDING
VOLTMETER
junction block, as shown in the accompany-
ing illustration.
2. Install a voltmeter as shown in the ac
companying illustration.
3. Warm the engine by running it for
about fifteen minutes at 1500 rpm or more.
4. Disconnect the regulator connector and
reconnect it to cycle the regulator.
5. Read the voltage on the voltmeter. If
the voltage reading is 13.5-15.2 volts, the
regulator does not need adjustment or re
placement. If the voltage is not within these
limits, leave the engine running at 1500 rpm
and proceed to step 6.
6. On Type One regulators, disconnect
the regulator connector and remove the reg
ulator cover. Reconnect the regulator con
nector. On Type Two regulators, remove the
adjustment screw access plug from the regu
lator case (the plug is actually an alien screw).
7. Observe the voltmeter reading and
turn the voltage adjustment screw until the
voltmeter reads 14.2-14.6 volts.
8. On Type One regulators, disconnect
AIR GAP
ADJUSTING NUT
ONLY
Type One voltage regulator—voltage adjustment
Schematic for testing the regulator voltage setting
ADJUSTING SCREW
(TURN TO ADJUST
VOLTAGE SETTING)
the regulator connector, install the cover and
reconnect the regulator connector.
9. Continue running the engine at 1500
rpm to re-establish the internal temperature
of the regulator (Type One only).
10. Again, cycle the regulator by discon
necting and reconnecting the regulator con
nector.
11. Recheck the voltmeter reading: If it is
between 13.5 and 15.2 volts, the regulator is
good; is not, replace the regulator.
CAUTION: On Type One regulators, al-
ways disconnect the regulator connector
before removing the regulator cover, to
prevent short circuits.
12. On Type Two regulators, If the volt
meter reading is okay, reinstall the access hole
plug.
VOLTAGE TESTING
Type Three Regulator Only
Though other tests of the internal voltage
regulator exist, the following test is quite ac-
curate and requires a minimum of tools.
NOTE: The following test must be per-
formed with the engine at normal operating
temperature.
1. Attach one lead of a voltmeter to the
"BAT" terminal of the alternator and the other
lead to a good ground.
2. Start the engine and operate at about
1500 rpm.
3. Observe the voltmeter reading: If it is
approximately 13.5-15.2 volts, the regulator
is properly limiting the voltage to the bat
tery. If the voltage is above about 15.2 volts,
replace the voltage regulator as previously
described. If the voltage is below 13 volts,
locate the test hole in the rear end frame of
REGULATOR