Microswitch water problem (1 Viewer)

[Dee101]

I have a 1995 Hymer and have just changed the bathroom tap as the microswitch had packed in. Now it’s a very simple job. There’s a red and black wire from the old tap, and there’s a red and black wire from the new tap. The new wires have been put where the old wires were. Yet now the microswitch in the kitchen sink (not the bathroom, the new tap in the bathroom works fine) will not work, unless I connect the new tap red and black wires underneath the bathroom sink, but that of course makes the water pump run continuously.
Any ideas anyone?

 

[KUSKUS]

Can you not put a meter on the two wires going to the micro switch and check resistance and see if microswitch has failed ?

 

[Lenny HB]

You may have fitted the wrong type of switch a normally open instead of a normally closed or the other way round. The ones in my van the switches were normally closed so when the tap was off it held the switch closed which meant the contacts were open.
I gave up got fed up with the wires/switches breaking every 6 months so I fitted a Shureflo pressure switched pump.

 

[Dee101]

That makes sense. Is there any way of changing them around?

Can you not put a meter on the two wires going to the micro switch and check resistance and see if microswitch has failed ?

Micro switch is fine, I think Lenny below may have found the fault. But what is the answer without buying a new pump, that is the question now!

 

[Dee101]

You may have fitted the wrong type of switch a normally open instead of a normally closed or the other way round. The ones in my van the switches were normally closed so when the tap was off it held the switch closed which meant the contacts were open.
I gave up got fed up with the wires/switches breaking every 6 months so I fitted a Shureflo pressure switched pump.

I will look into that if there’s no other solution. I just hope there’s a way with the wiring

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[the1andonly]

I will look into that if there’s no other solution. I just hope there’s a way with the wiring

If Lenny is right with the microswitch responce of normaly closed or normaly open and you have the wrong one, is not the answer get the right one.

 

[Dee101]

If Lenny is right with the microswitch responce of normaly closed or normaly open and you have the wrong one, is not the answer get the right one.

Obs the whole idea of my question- on a motorhome website, is to possibly find an alternative solution that negates the need to replace a brand new unit

 

[the1andonly]

Dee101 i'm obviously well confused. is the situation a microswitch has failed you have tried to replace it but its NC not NO (or via versa) if so use the correct item simples a microswitch is small beer. Or have you had to replace an entire tap. A shureflo pump maybe about £60 (£50 when i last bought one)

 

[Mike800966]

A lot of these microswitches are of the "changeover "type. If so it will have three tags on it, usually the one underneath is the common ,lever switch and the other are make or break,
Easy to check with a multimeter
Mike

 

[donkey]

Very simple to change to a pressure switch system and forget the micro switches. A Whale pressure switch can be added to the cold feed with either a 'T' or cut pipe and insert in-line. For wiring just run the pos feed to the pump via the Whale switch. If access is good, no more than an hours work.
No need to change the pump, will work with submersible or diaphragm type.

Geoff

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[Dee101]

Dee101 i'm obviously well confused. is the situation a microswitch has failed you have tried to replace it but its NC not NO (or via versa) if so use the correct item simples a microswitch is small beer. Or have you had to replace an entire tap. A shureflo pump maybe about £60 (£50 when i last bought one)

I’ve just received a reply from the retailer:

“Hi Many apologies for the delay
This tap, along with all the other micro-switched taps we sell, is a normally open switch
You may need to speak to an auto electrical specialist to resolve this if your system uses normally closed circuits
Hope this helps
Kind regards
Bob”

Which doesn’t move things forward. But I’m assuming that my other (existing) tap is a “closed switch” type. So I have a new open switch along with my existing closed switch (I presume). If you know of any way (other than buying another “open switch tap” to complement my existing newly purchased open switch tap) to get over this problem, it would be most appreciated

 

[donkey]

I’ve just received a reply from the retailer:

“Hi Many apologies for the delay
This tap, along with all the other micro-switched taps we sell, is a normally open switch
You may need to speak to an auto electrical specialist to resolve this if your system uses normally closed circuits
Hope this helps
Kind regards
Bob”

Which doesn’t move things forward. But I’m assuming that my other (existing) tap is a “closed switch” type. So I have a new open switch along with my existing closed switch (I presume). If you know of any way (other than buying another “open switch tap” to complement my existing newly purchased open switch tap) to get over this problem, it would be most appreciated

Please see my last post. Fit a Whale pressure switch and forget the problematic micro switch taps altogether.

Geoff

 

[Dee101]

Please see my last post. Fit a Whale pressure switch and forget the problematic micro switch taps altogether.

Geoff

But if someone says, “do such and such with the wiring,” that’s what I’ll do. We don’t have pressure issues with our pump. Nor microswitch issues until now. That’s got to be easier route…if someone on here knows how. Otherwise I’ll end up doing what you suggest

 

[autorouter]

I'm finding it hard to imagine a scenario where the wrong kind of microswitch can cause this problem. More likely the wiring has been disturbed somewhere.

Are you OK with using a meter to check resistance and continuity? You can check a microswitch with a meter to see if it's working, and if it's NC or NO. Use the lowest resistance range, or even better the continuity setting with a beeper if it has one.

The bathroom tap microswitch should show high resistance/no continuity when it's off, and low resistance/continuity beep when it's on. If it does the opposite then it's the wrong switching. But I don't think it's that otherwise the pump would be on when the tap is closed, and off when the tap opens.

Similarly you could check the kitchen tap microswitch, to see if it's actually switching when the tap opens. Then check at the kitchen tap wiring connection. Short the connector on the wire going to the pump with a link of wire/pair of scissors to see if the pump operates reliably.

 

[autorouter]

I’ve just received a reply from the retailer:

“Hi Many apologies for the delay
This tap, along with all the other micro-switched taps we sell, is a normally open switch
You may need to speak to an auto electrical specialist to resolve this if your system uses normally closed circuits
Hope this helps
Kind regards
Bob”

I think the retailer has got it the wrong way round. I suppose it depends on what you mean by 'normally'. But the usual definition of a Normally Closed (NC) microswitch is that it is closed when nothing is pressed/actuated on it, as when it is placed on a bench for testing. An NC microswitch will pass current when the button is not pressed in, and cut off the current when the button is pressed in. That's the kind you want for a tap.

From the point of view of the whole tap, I suppose you could say that 'normally' the tap is shut off, and the pump current is cut off so the switch is open, so in that sense it's 'normally open'. But the microswitch inside the tap is an NC type, and the button is pressed in when the tap is shut off.

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