How to Wire A Relay
Try to avoid powering your new accessories (ie; external fuel pump, cooling fans, etc) off smaller
gauge wires that were not designed to handle the additional loads.  Overloading a circuit could
cause shorts, melted wires, and even fires in your pride and joy.  There's nothing more time
consuming than chasing problems in your electrical system.  

The following connector locations will get you started on correctly wiring and adding components
to your electrical system.

  •  87        This is the full power output from the relay to your new component.
                Your new component will or should have it's own ground.

  •  85        This is to a solid frame or chassis ground.

  •  30        This is the power inlet to the relay from your positive battery post or
                switched 12 volt power source.  Consider mounting a proper size fuse
                in-line according to the demand of your component.

  •  86        This is the switched power source that turns the relay power to your
                component on / off.  It could also be the original power source to the
For example: If you have added an additional fuel pump or
                fog lights on your Mustang, this wire would be connected to the original
                power wire to that component or a tap into the fuse box under the dash.
                It could receive power from the Ignition-On position or you could use a
                switch in-line to cycle the power on / off as you please.  
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