3-Way Switch Wiring Question

johnmsch

Seaman
Joined
Jun 26, 2012
Messages
54
I've always done all the wiring on my boats and never had a problem, but this one has me pulling my hair out. I know I'm missing something obvious.

I replaced my old bilge pump (two wires) with a new Rule 750 (3 wires). Decided to replace the old lighted on/off rocker switch on my panel with a lighted 3-way. Found a source that sells the old McGill rockers, so I have an exact match on the style/size. Bought a few of these switches: http://www.oempartsllc.com/switchroc...0852-0180.aspx The intent is to push the top of the toggle and have the pump in auto mode, center position is off, and bottom is manual. No problem so far, but now I can't figure out how to get the light to work in either mode without everything coming on.

Here's the inside of the switch, with the rocker in place:
Switch-Rocker.jpg

Here's the inside with the rocker removed. I added the numbers as a reference point:
Switch-Inside2.jpg

Laying on its side, here's the back, with the corresponding reference numbers:
Switch-Bottom2.jpg

Now comes the weird part. Although its hard to see in the first two pictures, the bulb is hardwired between number 4 and 5.

Tried a couple different combinations, but ended with this, and it still does not look right:
1 - Brown (auto) wire from pump
2 - 12v+ fused
3 - Brown w/white stripe (manual) from pump
4 - jumper to #1 (how else would the light work?)
5 - Black (ground)

Flip the rocker to Auto, the light comes on. I press the test button on the pump and it comes on for a couple seconds. So far, so good.

Flip the rocker to Manual, the light comes on and the pump starts. But what I'm worried about is that with the jumper from #5 to #1, the Auto circuit is also energized. So, there would be the possibility that if the float were to close that circuit while the pump is already running manually, it might send the planet Mars hurtling through space and wipe out planet Earth.

Now I'm thinking I may have ordered the wrong switch. This one is Single Pole Double Throw. Will this work for what I'm trying to do (auto/off/manual)? Or should I be using a Double Pole Double Throw?

This is REALLY giving me a headache!
 

Q_ball

Seaman
Joined
Mar 26, 2009
Messages
61
Re: 3-Way Switch Wiring Question

I'm wiring mine up the same but i have a seperate float instead of internal like yours. first you need to to is a couple tests, if you apply 12v to the manual (BR/W) you should also show 12v on the auto (BR) wire and vise-versa if the float is closed. if this is correct here's what ya do.

1-auto brown
2-12v source
3-manual brown/white
4-ground(for light)
5-jumper to 3(for light)
when the switch is in auto the light will be off, float switch closes and sends power back along the manual wire intern completing the circuit for the light.
 

johnmsch

Seaman
Joined
Jun 26, 2012
Messages
54
Re: 3-Way Switch Wiring Question

Thanks! That makes perfect sense. I'll check that out tonight.
 

johnmsch

Seaman
Joined
Jun 26, 2012
Messages
54
Re: 3-Way Switch Wiring Question

Hey Q_ball - that works perfectly. Thanks again!!!!
 

Q_ball

Seaman
Joined
Mar 26, 2009
Messages
61
Re: 3-Way Switch Wiring Question

Your very welcome. Glad I could help.
 
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