Bilge Pump Question

I have a manual bilge pump now and plan on installing a new automatic pump. I saw a recommended wiring diagram which would require that I change the two-way switch (On/Off) on the dash to a new three-way switch (On/Off/Auto). A diagram of the suggested wiring is attached.

Attachment 15610


It worries me that if the switch on the dash isn't set to Auto, the pump won't run and my automatic pump won't be automatic. I thought a better way to wire the pump would be in this second diagram (hand drawn).

Attachment 15611

This way the pump will run if the boat starts to fill up with water, regardless of whether I forgot to leave the swith in the Auto position.

I'm wondering if I'm missing anything and if anyone has any input to what I think is a better approach. This way I also don't have to find a new three-way switch to fit in my dash where the existing two-way switch is now.

Any comments appreciated.

I replaced by bildge pump about 5 years ago with a float automatic pump. I only have the orignial on off switch on my boat and just wired to that. I usually just leave the switch on when I am fishing and it runs only when there is water in the well and it works just fine. I have not had any problems and my boat is in the water for 2 - 3 weeks at a time. No battery issues at all, I sometimes turn it off when I am out fishing but the downside of that is remembering to turn back on when I quit for the day. I think I bought a Rule pump and it works great, you don't need another switch.

I would just add an automatic pump, now you have two. It's easy to run an extra hose and fitting. You then wire the auto pump hot all the time. Two are better than one!!

The problem with leaving the auto bilge on hot all the time is when you take on a little water and the bilge kicks on all the time but really isn't removing any water. It's better to have an off switch for this reason and then turn your auto on at night if you leave your boat in the water. I actually cut my auto switch on the Rangers I had because I had trouble with the float sticking. That is the reason I would go with the three way switch instead of a two way switch. Just my two cents.

Not sure I understand why a 3 way would be better; if the float sticks on auto won't the pump turn on anyway? An on/off would do the same thing; you just need to remember to turn switch on at night or when raining as it will only run when water is present. You need to screen your openings so junk does not get in the pump.

Chip Vet, I know. I get so much sand from washing the carpet down the floor drain that it makes the float stick. Pain in the butt.