Bilge Pump Question
 

Now I know this is probably a dumb Q but I have never found the answer.

For bilge pump wiring there is always the auto-off-on switch with the three wires going back to the pump but why? I always run 12V hot to the float then to the pump, then ground the pump and also run the hot to a bilge switch on the dash. Gives me full time auto and manual override. Is there something I am missing? If I put in one of those auto-off-on switches what happens when the bilge fills and the switch is in off? And then what about auto? I just don't get it...

-Svence

Mine is wired from the float switch to the battery switch with simply an on off switch at the helm. I like having my batteries isolated completely when off, but others like hooking the float switch straight to one of there batteries. And yes, if you have the 3 way switch and your bilge gets water it will not pump out unless the switch is in the auto position. I've also seen people add an extra float switch higher up as an emergency protection that is straight to the battery.

So whats the deal with the damn 3 position switch then? When would I ever want to stop my bilge pump from pumping as water comes into the bilge... Doesn't make sense to me.

-Svence

You would have one wire from the auto side of the switch going to the float switch and one wire from the manual side of the switch going straight to the pump. This way you can select to run in auto, when the water level comes up the pump comes on automaticlly or you can choose to run the pump when ever you want in manual. Also if your float stop working you can flip it to manual and run that way.

If you rely on the float alone and it takes a dump then you can't run the pump. 3 Wires 1) from auto to float then to pump, 2) from manual to pump 3) ground wire.

Some auto/manual switches are set up to be momentary in the manual position which means you have to hold the switch when using manual. I like mine to be maintain, I flip it into manual and it stays till I turn it off.

Hope this helps.

See I get how it works I just don't understand why, and maybe I won't ever.

I get auto from my float, manual from my standard on-off switch, and no ambiguous middle ground where it won't even turn on if I am sinking.

-Svence

Some people do it for trailering purposes. Ever seen a bilge pump come on in a boat on a trailer at a red light? With a convertabile sitting next to the bilge outlet?:you: for you, not so funny to them:bat:.

See now that I can understand...

-Svence

So you are saying that you only have a on/off switch in your dash and the float wired straight to a hot.

That's how mine is, and my V-20 was wired the same way.

Thats correct. And I have the bilge pump grounded right to the battery making that 2 less wires I have to run all the way forward.

-Svence