Piper Arrow IV Turbo Maintenance Manual page 225

BATTERY BOX CORROSION PREVENTION.
The battery should be checked for spilled electrolyte or corrosion at least each 50 hour inspection or at
least every 30 days, whichever comes first. Should this be found in the box, on the terminals or around the
battery, the battery should be removed and both the box and battery cleaned by the following procedure:
1. Remove the box drain cap and drain off any electrolyte that may have overflowed into the box.
2. Clean the battery and the box. Corrosion effects may be neutralized by applying a solution of baking
soda and water mixed to a consistency of thin cream. The application of this mixture should be applied until all
bubbling action has ceased.
3. Rinse the battery and box with clean water and dry.
4. Place the cap over the battery box drain.
5. Reinstall the battery.
VOLTAGE REGULATOR. (Wico)
CHECKING VOLTAGE REGULATOR.
The regulator is a fully transistorized unit in which all of the components are encapsulated in epoxy, which
makes field repair of the unit impractical, and if it does not meet the specifications, it must be replaced. The
regulator may be tested by the following procedure:
1. Be sure that the battery is fully charged and in good condition.
2. Check the alternator according to the manufacturer's instructions, to determine if it is functioning
properly. This test must be done with the regulator out of the circuit. After completing this test, reconnect the
regulator into the circuit.
3. Use a good quality accurate voltmeter with at least a 15-volt scale.
4. Connect the positive voltmeter lead to the red wire at the regulator harness connector, or terminal
block. Connect the negative voltmeter lead to the regulator housing. Note: Do not connect the voltmeter across
the battery, because the regulator is designed to compensate for resistance contained within the wiring harness.
5. With the alternator turning at sufficient rpm to produce a half load condition, or approximately 25
amperes output, the voltmeter should read between 13.6 and 14.3-volts. The ambient temperatures surrounding
the voltage regulator should be between 50°F to 100°F while this test is being made.
PIPER AIRCRAFT
PA-28RT-201 / 201T
*MAINTENANCE MANUAL
—CAUTION—
Do not allow soda solution to enter battery.
1J9
24-35-01
Page 24-38
Revised: February 23, 1979