Bilge pump wiring...
 

As most of you may know I put a new engine and numerous other parts in the boat. I am installing a second bilge pump as a backup but ran into something I never saw nor heard of. I bought a brand new Rule float switch to install with a bilge pump I had lying around. The directions on this Rule switch say to install the wiring for the switch on the neg/ground wire. Every set up I saw in my life has the switch spliced into the pos/hot wire. Can their diagram be correct? Is this something new? Please help me out.
Thank you, Bob

Might be worth a call to Rule to ask why they want the ground wire broken by the switch.

It will work but be interesting to hear their reason for that way.

Maybe less chance of shorting the battery since the motor impedance will always be in the circuit if you put it in the neg side

Thanks for the fast reply men, I'm going with the old statement; always switch the hot side. Thank you both, Bob

From a pure electrical theory stand point, yes they are normally break the positive side but as long as the circuit loop is broke it really will not effect the operation.

For troubleshooting it is best to keep the same convention through out so it is standardized.

Let us know if you ever find out why they want it the other way.

If it was switched on the neg/ground side it would still work. I did read somewhere that a float switch will save on your batteries more so than an automatic style pump (one with a switch built in). It had something to do with an automatic having constant power to the pump while the float switch type only has it when the water rises and the switch makes contact. But yet this does not make sense. An automatic has power to it's switch located in the pump bottom. The other has power to the switch. The only difference is a couple feet of wire. Then again I don't know, Bob

I used to own a little rice burner with all the aftermarket lights, sound systems, and other accessories. I ALWAYS switched the negative side, and that is currently how my switch/pump is wired up in my boat... I have never had a problem.

Switching the negative side doesn't matter, but I wouldn't vary from positive to negative. In other words, make all switching the same.

Yes, I'll keep them all the same. As bad as my memory is it would only cause me problems. Thanks to all, Bob