Circuit for pump off - fan on, with float switch and relay

Thread Starter


Joined Aug 25, 2017
A 12V supply energizes the water pump until the low liquid level activates the float switch.
The pump then switches off.

How do I get the 12V supply to then switch automatically across to activate a 12V fan,
when the pump circuit is open/pump off?

I've though of using two liquid level control float switches, one upside-down, looped to the fan.
Alternatively, could I use a DPDT relay to run the 12V current to the fan when the pump is off?

Many thanks.