Relay question (1 Viewer)

[coldtaco]

So, trying to use a relay for the air horn installation. I am confused as to how a relay is supposed to work. My understanding is that points 85 and 86 are open until power (through a switch) is applied to 87, constant power to 30. Are 85 and 86 normally closed? When I check continuity between 85 and 86 without power to 30 and nothing hooked up to 87, I get continuity. How does 85 and 86 stay open until power is applied to 87?
30 is constant power
87 is for switch?
85 and 86 provide power to whatever you want to power?
Thanks

 

[coldtaco]

Someone provided a better diagram in my build thread and got it working now.
If a moderator wants to delete this thread that would be fine with me

 

[Omrib]

Just understood your last massage....
Deleted mine also.
Sorry for the misunderstanding

 

[Felde]

There are no dumb questions.
I'll explain it anyway, incase someone else stumbles on it...

85 and 86 make up coil that forms an electrical magnet. That's why there is continuity.
It pulls the contact that connects 30 and 87 when engaged.

The meaning of the figures is:

85 /86: Relais working circuit in / out. In essence, 85 is positive from the switch for the device and 86 is mass / negative.
30 battery positive , 87: Relais load circuit. In essence, the relais thus provides a switched positive at contact 87, good for 30 A.
Those figures are standardized here in Germany / Europe at least and go by the term ' Kfz Klemme'.
Cheers Ralf