Need three way toggle latching switch

[Jev88]

Hello Funsters.

I have a duff switch in my RV.

Pressing up and release should turn ON
Pressing down and release should turn OFF
Switch rests in the middle position and the system should stay on whatever the last press was - up or down / on or off.

Pictures of offending item.
I am hoping there is a simple generic similar switch I can install rather than trawling USA websites for what might be a simple switch!

 

[Sheddy]

Do a search using "2 pole momentary switch", you may find something that fits.

 

[Jev88]

Do a search using "2 pole momentary switch", you may find something that fits.

That's the sort of info I need as I don't know the correct terms for this type of thing.

 

[Two on Tour]

Momentary is what it says in that the contact is only made while the rocker of the switch is pressed and held and contact is lost when the rocker is released.
You need as you say a switch that latches on when pressed and unlatches on being pressed again.
These are readily available in a switch with a single rocker rather than a two way rocker.
Do you require this switch to keep the look and originality of your RV or will an alternative that will perform the same operation but look different do ?

 

[autorouter]

Are you sure it's the switch that does the latching? Maybe there's a latching relay, which requires a pulse in one direction to turn it on, and another pulse in the other direction to turn it off. And the switch just supplies the pulses to flip the relay from one state to the other. How many terminals are on the back of the switch, is it 4 or 6? Hard to tell from the picture.

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[Jev88]

Are you sure it's the switch that does the latching? Maybe there's a latching relay, which requires a pulse in one direction to turn it on, and another pulse in the other direction to turn it off. And the switch just supplies the pulses to flip the relay from one state to the other. How many terminals are on the back of the switch, is it 4 or 6? Hard to tell from the picture.

You are right. The switches flick relays under the dash.

FOUR connections on each switch and these cross over copper connections you can see run diagonal. One switch for cab and one for chassis (as the Americans put it). One switch must not be sending a pulse as direct power to the relay works fine but the switch is not doing its thing and feels "stickier / stiffer" than the neighbouring switch that does work.

So what are they correctly called? Centre wires are just an led that tells you if you are latched on or off).

 

[autorouter]

There's more than one way to implement a latching switch with relays. Is there any part number or any writing at all on the existing switch? Maybe something like NO or NC (Normally Open or Normally Closed)?

 

[Brianmor]

Stupid question, can you disassemble the offending switch and clean it, or even spray it with decent switch cleaner

 

[Jev88]

There's more than one way to implement a latching switch with relays. Is there any part number or any writing at all on the existing switch? Maybe something like NO or NC (Normally Open or Normally Closed)?

Absolutely no writing or labels whatsoever!

Stupid question, can you disassemble the offending switch and clean it, or even spray it with decent switch cleaner

Sealed unit - can't see anything to prise apart!

 

[Brianmor]

I think the toggle will come away from the body at the front, I've seen similar before and have successfully dismantled for cleaning.

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[TheBig1]

I have not seen a prewired crossover switch with bare copper tracks on the back for a while. In essence it is a six terminal 2 pole switch, the same as a window switch

 

[Jev88]

I have not seen a prewired crossover switch with bare copper tracks on the back for a while. In essence it is a six terminal 2 pole switch, the same as a window switch

That's why I am here to work out what is really needed. This switch is 23 years old. There are still cross over units available in varying designs but I wanted to check what I should be looking for.
I also don't understand how the switch & relay works - send a pulse to energsie the relay int a position - ok, I get that. But then the rocking switch going back to centre and the relay stays as it was? What holds it in place?

 

[TheBig1]

positive and negative in to the copper strips, pressing the button connects the terminals so the 2 wires out change polarity +- / -+

 

[Jev88]

positive and negative in to the copper strips, pressing the button connects the terminals so the 2 wires out change polarity +- / -+

I will probably try one of these....

Amazon product ASIN B0B2P5S34K

 

[TheBig1]

I will probably try one of these....

Amazon product ASIN B0B2P5S34K

That will work if the cut out is the same size

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[autorouter]

That one is correct, it's a 2-pole momentary changeover switch, which is called a 2-pole '(On)-Off-(On)' Rocker Switch. The brackets are important, it means the two 'On' positions are momentary not latched, and the switch returns to the centre off position when released.

If that doesn't fit in the hole, you could use one with 6 terminals, and no copper strips, they might be easier to get in the correct size. You could connect the opposite pairs of terminals with a wire link instead of the copper strips. Make two Y-connectors, 1 male to two female spade connectors. Connect one of the existing wires on the end terminals to the male connector, and the two female connectors bridge across where the copper strips would go. The same for the other wire on the end terminals. The wires to the centre terminals just transfer to the same terminals on the new switch.

The relay has two positions, held in place by a spring. A small push flips it from one state to the other, much like a manual switch clicks from one state to the other. A coil provides a force to flip it. Reversing the coil polarity pushes in the opposite direction. The 2-pole changeover switch is the method used to reverse the polarity of the pulse.

 

[Jev88]

That one is correct, it's a 2-pole momentary changeover switch, which is called a 2-pole '(On)-Off-(On)' Rocker Switch. The brackets are important, it means the two 'On' positions are momentary not latched, and the switch returns to the centre off position when released.

If that doesn't fit in the hole, you could use one with 6 terminals, and no copper strips, they might be easier to get in the correct size. You could connect the opposite pairs of terminals with a wire link instead of the copper strips. Make two Y-connectors, 1 male to two female spade connectors. Connect one of the existing wires on the end terminals to the male connector, and the two female connectors bridge across where the copper strips would go. The same for the other wire on the end terminals. The wires to the centre terminals just transfer to the same terminals on the new switch.

The relay has two positions, held in place by a spring. A small push flips it from one state to the other, much like a manual switch clicks from one state to the other. A coil provides a force to flip it. Reversing the coil polarity pushes in the opposite direction. The 2-pole changeover switch is the method used to reverse the polarity of the pulse.

Great explanation thanks. I tested the old relay with a battery and it would not hold one position - always fell back.

 

[Gromett]

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Momentary-off-momentary