Round Motor
Fig. 7 Gear box relay and drive gear assembly, shown in park position. Compound wound round windshield wiper motor:
Fig. 14 Connections to operate compound wound round wiper motor independent of vehicle wiring:
On models with pulse wipers, refer to ``Multiplex Wiper System'' for testing procedures.
WIPER INOPERATIVE
1. Remove washer pump to gain access to relay switch assembly.
2. Connect 12 volt source to wiper, feed side to center terminal, ground side to gear housing, Fig. 14. Do not connect jumper to terminal 1 and 3.
3. To determine if relay coil is open, connect test lamp to wiper terminal No. 1. Test lamp should light.
4. Test relay switch as follows:
a. If gear mechanism is in full park position insert a small screwdriver into the switch slot (between the drive pawl and the relay latch arm) and push relay latch arm downward and toward the relay coil in direction of the arrow, Fig. 7. Next, remove a small amount of insulation from black lead with pink tracer and touch test lamp to exposed wire.
b. If test lamp lights but motor doesn't run, proceed to step 5.
c. If test lamp doesn't light, relay switch is defective. Cover exposed wire with tape after the test.
5. Disassemble motor section and check the following:
a. Hung brush.
b. Solder connections at brush holders.
c. Splice joints at field coil connections to leads.
d. Open armature.
e. Circuit breaker ground connection on field lamination.
f. To check the circuit breaker, disassemble motor section of wiper and visually inspect the circuit breaker for dirty or burned contacts or solder connections.
Fig. 14 Connections to operate compound wound round wiper motor independent of vehicle wiring:
Fig. 15 Gear box relay & drive gear assembly inspection:
WIPER WILL NOT SHUT OFF
Crank Arm Rotates 360 Degrees
1. Observe if relay latch arm spring is connected properly, Fig. 15.
2. Manually operate latch arm to check it for possible binding condition.
3. If items in 1 and 2 check out, connect power source to wiper and connect jumper wire from terminal No. 3 to wiper housing. DO NOT make any connections from terminal No. 1. Manually actuate latch arm in direction of arrow, Fig. 15, and observe if it remains in energized position (inside plastic switch housing out of path of gear drive pawl). If it remains in energized position, check for grounded red lead from coil to terminal No. 1. If red lead is not grounded, coil is probably grounded internally and relay switch should be replaced.
Recycles
Crank arm oscillates in a somewhat horizontal plane and is accompanied by a loud knock with each revolution of the gear.
1. Check that drive pawl and relay latch arm springs are properly connected, Fig. 15.
2. Check wiper for LO speed operation, Fig. 14. If wiper has HI speed only, check the following items:
a. Solder joint at No. 3 wiper terminal.
b. Splice joint-field coil crossover splice.
c. Splice joint-black lead to field coil.
3. Check relay switch as follows:
a. Remove small amount of insulation from black lead with pink stripe and connect test light between exposed wire and wiper housing.
b. Connect positive side of power source to terminal No. 2 and negative side to motor case. Install jumper wire from terminal No. 1 to motor case. Observe if test light goes out once for each revolution of gear or if light glows steadily. If light glows steadily, relay switch contacts are not opening and switch is defective. If light goes out each time drive pawl moves into relay switch slot, relay switch is functioning correctly.
WIPER HAS ONE SPEED, LO
1. Check for grounded condition in the internal black lead that connects to wiper terminal No. 3.
2. Disassemble motor section of wiper and check for grounded shunt field coil.
Fig. 16 Gear box relay terminal board resistor:
WIPER HAS EXCESSIVE SPEED IN HI BUT LO SPEED IS NORMAL
1. Check for open 20 ohm resistor and the resistor ground connection, Fig. 16.
Fig. 14 Connections to operate compound wound round wiper motor independent of vehicle wiring:
Fig. 17 Round wiper motor current draw specifications:
INTERMITTENT OPERATION
1. Check solder connections at wiper terminal board.
2. Connect wiper to operate in LO speed, Fig. 14. Connect ammeter (range 0---30 amps) in feed wire circuit to wiper and observe current draw. Allow motor to run until it becomes hot; see Specification Chart, Fig. 17.
a. If current draw is normal and wiper cycles on and off, a weak circuit breaker is indicated. Replace brush plate assembly.
b. If current draw exceeds specification, proceed to Steps 3, 4 and 5.
3. Adjust armature end play as required armature on growler for shorted or grounded condition.