Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by BigKev On 2023/1/5 7:46:36

A relay is just an electronic switch. So in its simplest terms there are two terminals that carry the high amp load. So 6v coming in from the battery and another going out to the load (lights, fan, heater, etc)

Then there are two other terminals that control the switch. So one of those is usually connected to ground and the other to a 6v switched power source.

So when the the switched source is turned on it it activates the relay (turns it on).

The entire purpose is that the switch terminals only require very low average to active the relay which then switches on the high amperage load. So in your situation, the ignition switch wpuld be supplying the low amperage signal, vs high amerage load.

Think of it as master - slave switch.

Relays usually have more than 4 terminals, (usually 5). So you wire them in either normally off, or normally on configuration