How to test an electromagnetic float switch out of the boat

[viper1216]

Looking to test my float switch to see if it's working. I recently replaced the bilge pump...and not 100% positive I am connecting the wires back together correctly...pretty sure, but want to rule out the switch definitively before I buy a new one. Switch is a Johnson Model 3615 Automatic Float switch (it's red, not black one that I keep seeing online) . It has 3 wires (Brownn/red, Brown, black). I have it out of the boat and am trying to figure out how I can test it. Assuming I need to attach it to a battery since it's electromagnetic....so Brn/Red to Bat+ and black to Neg...should Brown get hot when I activate the switch manually? I went through hell getting this new pump and the existing float switch mounted, so hoping I'm just missing something in the wiring on the boat. The bilge works fine on the dash switch, just not auto when I hit the float switch manually. Any and all insight very much appreciated as always!!!

 

[Alumarine]

I don't think it needs to be hooked up to a battery to test it.
If you have a meter check for continuity between the brown-red and the brown when the switch is activated.

Basically the switch connects/disconnects the brown wires.

 

[Scott Danforth]

hook a meter up to it and lift

 

[viper1216]

But it's electromagnetic...wouldn't you need 12v to power the magnetic connection? Can't be a regular on off connection due to spark....anywho...I hooked it up to a battery...12v to the red/brn wire and blk to ground. In theory, when I activate I should get 12V to that other brown wire...got nothing...so I'm saying bad switch. Which brings me to next issue...most float switches I have seen are 2 wire....can I replace a 3 wire switch with a 2 wire? Or is that going to require a whole bunch of re-wiring?

 

[Scott Danforth]

no, its a switch. the magnet moves with respect to the reed switch. a 3-wire switch using a reed switch and magnet will have ground, power and load.

a two wire switch using a mercury capsule or other, etc will have power and load.