Ariens HVZ 915085-2350 Service Manual download pdf (Page 36)

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L and S. These connections apply power to close the

solenoid contacts and operate the starter motor.

In addition to the above test, place the switch in the run

position and check between each contact and ground

(metal case) to be sure no terminals are grounded. If

the switch is operating properly, there will be no

continuity between contacts other that those described.

11.5 SOLENOID AND RELAYS

Solenoid and relays are both magnetically operated

devices. Both devices operate on the principle that

passing a current of electricity through a coil of wire will

create a magnetic field strong enough to attract a piece

of iron or steel. Each device uses this principle in a

slightly different manner.

Relay - A basic relay (Figure 28) consists of a coil of

wire wound around a soft iron (magnetic) core. When

current is passed through the coil, the core is

magnetized and pulls down on a magnetic lever. The

lever in turn is attached to several switch contacts

which open or close other electrical circuits. In this

fashion, a small current can control one or more larger

electrical currents and actuate several other devices. In

most cases a relay contact moves only a fraction of an

inch and the magnetic pull is small.

Figure 28

Solenoid - A basic solenoid (Figure 29) consists of a

coil of wire wound around a hollow tube. A magnetic

core slides inside the tube. When current is passed

through the coil, the core is pulled into the solenoid with

considerable force. With proper design, a solenoid can

exert considerable force over a distance of several

inches. A solenoid can therefore, pull a lever, close a

heavy contact, or perform other jobs that require a

straight line pull.

Figure 29

If a relay or solenoid fails to operate, the cause may be

either electrical or mechanical.

To check electrically, connect a voltmeter across the

coil of the device and activate the circuit that operates

the relay or solenoid. If the meter indicates no voltage

is applied, the cause is in the control circuit.

If the meter indicates proper voltage across the coil but

the device does not function, remove the power,

disconnect the wiring and check the continuity of the

coil with an ohmmeter. The meter should indicate

resistance, in the order of 3 to 5 ohms, if the coil is

intact. A high resistance indicates an open coil and a

defective device.

There are also a number of mechanical problems that

may cause the problem.

The starter solenoid in the Ariens equipment is a

sealed unit used to actuate the starter motor on the

engines. These solenoids may have three or four

connections. The two large connections carry high

current to operate the starter motor. The small

connections are connected to the coil and carry the

control current.

To check the solenoid, disconnect the cables to the

starter motor, turn the ignition switch to the start

position, and listen for the solenoid to snap inside

contacts closed.

If no snap is heard, check across the coils with a

voltmeter. The voltage should read 12 volts with the

ignition switch in the start position. If no voltage

appears, the defect is in the start circuit.

If the voltage is correct, turn off the power and check

continuity of the coil with an ohmmeter. If the coil is

open, the solenoid is defective and must be replaced.

If the coil has the proper voltage applied, and the

continuity check indicates the coil is intact, the solenoid

plunger is stuck or the contacts are welded shut and

the solenoid must be replaced.

If the solenoid snaps shut, but the starter does not

operate, check across the large contacts with an

ohmmeter. If there is no continuity when the solenoid

snaps shut, the contacts are defective and the solenoid

must be replaced.

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