Service Manual

Part Numbers
47-1910
Purpose
The solenoid’s purpose is simply to protect the ignition switch from the
high current drawn by the starter motor.
How It Works
The solenoid has really only two parts. One is a coil of wire wrapped
around an iron core. Whenever 12 volts is applied to the coil, it becomes a
magnet. The other part is a steel bar type switch. Because it is made of
steel it can easily handle the high current loads produced by the starter
motor. So how does it protect the ignition switch? When 12 volts is applied
to the coil, it becomes an electromagnet. This quickly pulls the steel bar
toward the contacts and closes the switch. When power is removed from
the coil, the spring loaded bar returns to its “normally open” position. Note:
The solenoid closes and opens the switch very quickly. This minimizes the
“arcing” that can damage other type switches.
Testing
1. Disconnect the solenoid from the wiring harness.
2. Check to ensure that terminals “c” and “d” are not continuous.
3. Apply a 12 volt power source to “a” and “b” terminals. You should be
able to hear the solenoid switch “click” when you make the connection.
4. Verify that the switch has closed by making sure that terminals “c” and
“d” are closed when power is applied to terminals “a” and “b”.
Solenoid
Glossary
GLOSSARY
3-18 Demystification Guide