how relay works ? Options

[jimkelly]

and can some describe how a relay works?

is it that HIGH AMPERAGE thru 85 and 86 operate a switch, and when switched send LOW AMPERAGE thru 30 and 87? what is 87A's purpose?

[jimkelly]

I believe pin 30 is always connected to either 87 or 87a.

in my diagram, pin 30 is high current 12V. the fog lights get grounded.

85 (ground) and 86 (low current 12v) make the circuit for the low current switch.

when the low current switch is activated, the high current circuit is engaged between 30 and 87.

I believe i got that right?

I edited this diagram to make up mine, as it seemed the most straight forward.

interesting that fig B would require the use of all 5 pins on the relay. B is actually far slicker : )

[Spoke]

I believe pin 30 is always connected to either 87 or 87a.

in my diagram, pin 30 is high current 12V. the fog lights get grounded.

85 (ground) and 86 (low current 12v) make the circuit for the low current switch.

when the low current switch is activated, the high current circuit is engaged between 30 and 87.

I believe i got that right?

I edited this diagram to make up mine, as it seemed the most straight forward.

interesting that fig B would require the use of all 5 pins on the relay. B is actually far slicker : )

You are correct.

Pin 30 switches between 87 and 87a.

When 85-86 = 0V; 30 = 87a; 87 open
When 85-86 = 12V; 30 = 87; 87a open

For Fig B, when the high beams are turned on, the relay coil is powered (85-86 = 12V), 30 = 87 and the fogs are off.

With high beams off, 85-85 = 0V and 30 = 87a and power to fogs comes from 12V positive from headlight switch.

A question with Fig B is that the switching on/off of the fogs comes from the 12V positive from headlight switch. What is the circuit for 12V positive from headlight switch? Is this another relay? It must be to switch the high current of the fogs.