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?

[arcadeforever]

from what I can see.... oddly enough it appears 87a has no purpose, its a pole for whatever event 85 and 86 do to 30 that make 30 switch to 87 (85,86 could be the grid for a rear defroster system(just a wild guess)). Im not sure WHY 87a has nothing hooked to it. I guess Id have to see the rest of the schematic.

this is a SPST (Single Pole Single throw) switch/relay. relays have tons of applications, this is a pretty smart relay where the sensor within the relay switches the load, typically, what they pretty much do is use a low power circuit to turn on a high power circuit. A relay in a fog light scenario, where, when two terminals are connected via a switch will actuate a high current switch that turns on the lights.

You cant eliminate the relay in this type of circuit or you will watch the switch in your dash melt into a puddle (IMG:style_emoticons/default/smile.gif) The relays' high current contacts are made of MUCH thicker metal so it can handle the current/heat.

The double relay for the FI system is an amazing little relay that gets switched on when the key turns to on and ALSO has a set of inputs from the AFM that turn on the fuel pump, so basically the fuel pump gets turned on with the AFM is actuated meaning the engine is creating vacuum. Of course it does more than that...

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?