What is the purpose of the ignition switch?
by Michelle Schaefer. The ignition switch in a motor vehicle is the main electrical component used by the operator to start, run and turn off the vehicle. The main purpose of the switch is to allow the operator to safely engage the ignition system and activate the electric starter.
How is the starter wire connected to the ignition switch?
This wire energizes vehicle accessories such as the radio when the ignition switch is turned to the “ACC” position. Connect starter relay wire to the “ST” terminal of the ignition switch. The “ST” terminal only activates when the ignition switch is turned to the “START” position and is a spring-loaded momentary contact.
What are the four positions of an ignition switch?
A Common Ignition Switch Has Four Positions OFF – Or LOCK position – Turns off power to the engine and electrical accessories ACC – Accessory position that provides power to electrical accessories only, not the engine. RUN – The “ON” position that provides power to the engine and electrical accessories.
Where does the ignition warning light come from?
The wire runs from the alternator through the bulkhead and up to the warning light mounted in the dashboard. From here it runs to the ignition/starter switch. In general, if the charging system is working normally, the warning light should glow when the ignition is switched on and then extinguish when the engine is started.
Why does the ignition switch need to be in the Accessory position?
The ignition switch must be in this position before the driver can remove or insert the key. Accessory: In this position, the ignition switch supplies battery power to the vehicle’s accessories, such as the radio and lights. But it doesn’t provide power to the engine control circuits.
This wire energizes vehicle accessories such as the radio when the ignition switch is turned to the “ACC” position. Connect starter relay wire to the “ST” terminal of the ignition switch. The “ST” terminal only activates when the ignition switch is turned to the “START” position and is a spring-loaded momentary contact.
Where does the power from the ignition switch come from?
The ignition switch supplies power from your battery to most of your car’s electronics. Which parts get that power depends on where you turn the switch after you insert the car key. Which parts get that power depends on where you turn the switch after you insert the car key.
What happens when the ignition switch is off?
Generally speaking, in the “OFF” position, the ignition switch doesn’t connect anything; in the “ACC” position, the radio or fan may be energized; in the “RUN” position, the engine control module is energized; and finally, in the “START” position, the starter relay is engaged. (These generalizations, depend significantly on year, make, and model.)