Piper Arrow IV Turbo Maintenance Manual page 678

CRANKING.
MAINTENANCE OF STARTING SYSTEM.
The starting circuit should be inspected at regular intervals, the frequency of which should be determined
by the amount of service and the conditions under which the vehicle is operated. It is recommended that such
inspection be made at each 100 hours and include the following:
1. The battery should be checked with a hydrometer to be sure it is fully charged and filled to the proper
level with approved water. A load test should be made to determine battery condition. If dirt and corrosion
have accumulated on the battery, it should be cleaned with a solution of baking soda and water. Be sure none
of the solution enters the battery cells.
2. The starting circuit wiring should be inspected to be sure that all connections are clean and tight and
that the insulation is sound. A voltage loss test should be made to locate any high-resistance connections that
would affect starting motor eff i c i e n c y. This test is made with a low-reading voltmeter while cranking the
engine or at approximately 100 amperes, and the following limits should be used:
A. Voltage loss from insulated battery post to starting motor terminal - 0.3-volt maximum.
B. Voltage loss from battery ground post to starter frame - 0.1-volt maximum.
If voltage loss is greater than the above limits, additional tests
should be made over each part of the circuit to locate the high
resistance connections.
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
Figure 80-1. Exploded View of Gear Reduction Starting Motor
—NOTE—
3G15
80-10-01
Page 80-04
December 1, 1978