Just need to double check

[paultallett]

My engine room electric bilge pump has seen better days so decided to replace it yesterday. It consisted of a Johnson pump and a separate float switch. It was permanently in auto mode unless I flick the switch on the dash that would then turn the pump on.

The pump had a positive and negative wire, the float switch a positive, negative and a switch wire.

The new pump has a built in float switch and as such, consists of positive, negative and a switch wire.

So I started with 5 wires, 2 x +, 2 x - and a switch....... Now I only 3 wires and it's deciding which goes to where.

I've connected the old pump positive and negative wires to the new ones, then I've attached the old float switch, switch wire to the new pumps switch wire. I've taped up the old float switches positive and negative.

As the boats out of the water and my batteries are at home, I couldn't test it yesterday. does this sound right?? All of the old wires and new wires are easy to swap around if I'm wrong, not made any proper sealed connections yet, I wanted to get some advice before I did that.

 

[James L]

I would think you should have connected the float switch wires, you know these must have always been live as the float switch always worked.

 

[paultallett]

I would think you should have connected the float switch wires, you know these must have always been live as the float switch always worked.

That was my plan B, Plan C being to bring the + together, - together...... Wanted to get advice before I do anymore

 

[jfm]

A float switch (the old one) with +, - and sw it must be some sort of powered float switch. A passive float switch would have only 2 wires.

Anyway, you need to find a -, a permanent +, and a wire that goes + when the dash switch is flicked on. Those are almost* certainly the three wires you have connected to your old float switch. You should connect these to -, + and switched on the new pump. The + and - to your old pump can be stripped out.

*It's not ideal doing this on a forum. It needs to be done with batteries and a multimeter unless you can see all the relevant wires with your eyes

 

[paultallett]

A float switch (the old one) with +, - and sw it must be some sort of powered float switch. A passive float switch would have only 2 wires.

Anyway, you need to find a -, a permanent +, and a wire that goes + when the dash switch is flicked on. Those are almost* certainly the three wires you have connected to your old float switch. You should connect these to -, + and switched on the new pump. The + and - to your old pump can be stripped out.

*It's not ideal doing this on a forum. It needs to be done with batteries and a multimeter unless you can see all the relevant wires with your eyes

Thanks for the reply, I'm thinking thats the best way forward. Wait until I have her ready to float again and do the testing with the multimeter.