Question about automotive relays

[OneRedLT4]

I don't know much about automotive relays and what trips them and such, but I'm wondering if they are something that will do what I need.

Essentially I need a normally open contact to close when power is supplied, but I don't want the power that trips the relay to be the power that is allowed through and powers the target device.

I work at times with these little simple relays that sit in a normal state at rest, then when you apply 12VDC (for example) to the + and - terminals, the state changes to off normal. I'll have the positive lead of 13.8VDC running through the normally open side and about 12VDC being the trigger.

Are the automotive relays something that does things this way? I have one of these compact relays under the hood now liberally coated in liquid tape to protect from the elements for now, but would rather use something better suited for the environment.

Page: ELK Website

 

[auntiebling]

Yes. That's how all relays work. The number of switches and "normal" condition can get dizzying though.

 

[Loopey]

They are identical to the unit you posted.

Typically they are 4 terminal since most automotive applications do not need power in the "off" position.

Trigger across 85 & 86. Power through 30 & 87.

Terminal 87A is deleted on many.

 

[Climber]

Check out motorcycle starter relays (Starter Relay), that should do what you want and handle a big load.

 

[OneRedLT4]

They are identical to the unit you posted.

Typically they are 4 terminal since most automotive applications do not need power in the "off" position.

Trigger across 85 & 86. Power through 30 & 87.

Terminal 87A is deleted on many.

That's actually better as when I was at parts store, I saw the female plug with leads. I could mount to fender well.

 

[OneRedLT4]

Thanks for the responses. I got it installed nice and clean, and correctly.