How do most manufacturer's "NORMALLY" wire relays

[bumperm]

Re: Question on Electrical Relay on engines

Excellent synopsis.

Thank you :c)

I should have added, when attempting to "jump start" any machinery, make double **** sure you or anything else you care about is not in the way. Vehicle in neutral, brake on, wheel chocks, etc. One poor guy posted here some time back about running himself over while shorting across the starter relay as I've described . . . really messed him up. Hope he's doing much better now. Be careful please. And if you don't know what you're doing, don't.

 

[k0ua]

Re: Question on Electrical Relay on engines

Thank you :c)

I should have added, when attempting to "jump start" any machinery, make double **** sure you or anything else you care about is not in the way. Vehicle in neutral, brake on, wheel chocks, etc. One poor guy posted here some time back about running himself over while shorting across the starter relay as I've described . . . really messed him up. Hope he's doing much better now. Be careful please. And if you don't know what you're doing, don't.

Yes. I wish they would teach some of these basic things and the theory behind it in school. And yes the good safety practices too.

 

[Soundguy]

sad part about that guy ( in the UK ? ) that got run over.. was that I don't think he was trying to jump the starter.. i think he dropped a tool on the relay and that 1 in a million chance it shorted and welded the tool on and started moving..

 

[whiterose]

Yes fully concur with LD1 in that explanation. And rightly as said this system allows a small current that is easily handled by the ignition switch to control the very high current that the starter needs. The device referred to as the relay can also be called the starter solenoid or even a contactor- all the same.

The only thing stopping the starter from being activated is the large contacts in the solenoid switch are not being 'made/contacting/together'. When the ignition is turned to 'start' a small current is sent to the terminal on the solenoid that makes it 'pull in, come together close/switch on.
As soon as the engine starts the ignition keyis let go of and it returns by spring away from its 'start' position, the relay/solenoid drops out ( turns off) and the starter motor is de-energized.