Adding a float switch to a Shurflow 4008-171-E65 pump

About a year ago I got a Shurflow 4008 RV pump to move water out of my rain barrels.  I've used it on and off since then.  I ran into a few issues.  The first is that I ran out of water frequently.  I'm hoping that I have alleviated that problem by adding more barrels.  The other, and bigger issue is that the pump doesn't shut off when the barrel is empty.  It just continues to run and get very hot.  I needed to add a float switch to keep this from happening.

The float switch opens and closes a circuit depending on the angle of the float.  When the barrel is empty the pump will shut off.

I started by putting 3/16" quick disconnects on two wires of the float switch. I had to order the male disconnects from Amazon.  The female ones came from Auto Zone.

One end of the pump had two wires going into with with female disconnects. 

I filled a barrel with water and put the float in it.  I had to play around with the location of the weight.

Then I connected the male disconnect on the float switch to the female disconnect on the pump.  The female disconnect on the switch connected to the pump.

 Below is a picture of it all hooked up.

I plugged in the pump and drained the barrel.  When it was nearly empty the pump shut off.

I did have to play with the weight and the length of the cable a little bit to get things just right.  I don't want the pump to shut off when there's still plenty of water in the barrel, and I don't want it to run when there's no water left to draw.

The final step was to drill a hole in the lid, insert a grommet, and run the 10' cord through it. 

I put the lid on one of the newly installed barrels.  Now I just need to get the pump out there in a more permanent location.