The diagrams and photos show how to wire up the fuel pump and oil-pressure switch to a commonly available, industry standard, ISO-type "1 Form C single pole/double throw" (SPDT) relay.

2. Switch between 2 different Loads with DPDT switch In this second application we can use the DPDT switch to choose between 2 different load and have a visual indication of what load is connected. In ...

Wondering how exactly you would wire an electric fan with a relay on your classic car or hot rod? Well, you came to the right place.