Piper ARROW III, Service Manual

Page: 370 / 594

8A-33. REMOVAL OF HARNESS.
a. Disconnect the clamps that secure the wires to the engine and accessories.
b. Loosen the coupling nuts at the spark plugs and remove the insulators from the spark plug barrel well.
Use caution when withdrawing the insulator not to damage the insulator spring.
c. Place a guard over the harness insulators.
d. Remove the harness assembly terminal plate from the magneto.
e. Remove the harness from the airplane.
8A-34. MAINTENANCE OF HARNESS.
a. To replace contact springs, spring retainer assemblies or insulating sleeves, proceed as follows:
1. Using a Scintilla 11-7073 Needle or a mechanical pencil with the lead retracted, hook the end of
the contact spring as shown in Figure 8A-16.
2. Using the needle or pencil, unscrew the spring.
3. Slide insulating sleeve and spring retainer assembly off end of lead assembly.
4. Replace defective component and reassemble as follows:
(a) Fabricate a tool as shown in Figure 8A-17 for installing the insulating sleeves over cable
terminals.
(b) Push the tool through insulating sleeve and spring retainer assembly as shown in Figure 8A-
18. Screw the cable terminal into the tool.
(c) Work insulating sleeve and spring retainer assembly into position over the cable and unscrew
the tool. Install contact spring on cable terminal.
NOTE
It may be necessary to lubricate cable and insulating sleeve with a thin firm
of MC 200 (200,000 centistokes) or commercial grade alcohol to facilitate
assembly.
b. To replace one of the lead assemblies, proceed as follows:
1. Remove clamps and brackets from applicable lead assembly. Cut cable ties from assembly and
discard.
2. Cut off condemned lead flush with outer surface of cable outlet plate.
3. Grip eyelet of lead with a pair of pliers and pull short length of conductor out of grommet and
cable outlet plate.
4. Using a 3 inch long, 0.270 inch diameter drift, applied at outer surface of plate, drive out tapered
ferrule and remaining pieces of insulation and shielding.
5. To determine what length the new lead assembly should be cut to, proceed as follows:
(a) Measure the length of the condemned lead assembly. Move coupling nut back on lead
assembly and measure from outer end-of ferrule at spark plug end. (Refer to Figure 8A-19.)
(b) To the length determined in Step (a), add 1-3/4 inches.
NOTE
Spare part leads are supplied in various lengths. Use a lead which is longer
than, but nearest to, the desired length.
Revised: 8/31/77
2D20
CHEROKEE ARROW III SERVICE MANUAL
POWER PLANT - LYCOMING