12V water pump circuit

Generally the switches are wired in parallel, positive to the switch then
to the pump, earth on the other side of the pump, pretty simple.

Generally most use taps with switches in them, the water will only run through the tap
that is open.

If you don't have taps as such then you would need to run from the switch to the
solenoid then from the solenoid to the pump through a suitably rated diode. The diodes
will prevent the positive feedback to the other solenoid.

Another option would be to use a relay with a changeover contact, one switch operates
the solenoid and through the break contact to the pump.

The other switch operates its solenoid and the relay and connects to the make contact
of the relay.

The pump is connected to the lever spring contact.

Principle of operation is switch one operates its solenoid and through the realy the pump.
Switch two operates its solenoid and the relay and through the relay to operate the pump.

Hope that makes sense.

Taps are pretty reliable :)

Cheers,
Peter
OKA196 Motorhome.

Perhaps you could try something like this.
The pump will turn on when either switch (or both) is closed, but closing a switch will only open the associated solenoid, and not the other.

Ken

If you are trying to minimise weight then keep in mind that adding a second pump will add perhaps up to 2kg.
If you use the single pump configuration and use one half of a bridge rectifier as shown below then you would only add ~ 20g, however you may need to mount the device on a small heatsink.
The cost of the rectifier as shown is only $5.50 at Jaycar.

As shown in the diagram, only one half of the bridge is used, but the package is convenient and easy to use and mount..

Ken

Maybe I am missing some important detail here, has been known to happen (;=)) but wouldn't a pressure controlled pump such as a Sureflo as used in most vans be a much simpler way out. Just an isolating switch between the battery and pump.
Either tap being turned on causes a pressure drop and activates the pump. Turn the tap off and the restoration of pressure switches the pump off.

Cheers
Pop

With all due respect, aren't you over complicating the issue. Why not use a single pressure pump configuration?

thanks again.

Last night I ordered another pump...$29 including postage.

From a "Y" fitting from the tank the systems will be totally separate. See my "taps" aren't taps. The sink is a straight through spout with just a toggle off/on switch beside it and the shower is a straight hose to a camping shower head, again not a tap and with an off on switch. So full control must come electrically.

Hence the posts about diodes etc to prevent the other line running water when you want the firs tone only.

So never mind now, easy solution to buy a second pump.

Regards to all

Yes Pop. think you have it.

This was the original purchase. Last night I purchased a second pump alone for $29.90. They say they have a "check valve". I imagine that means a built in one way valve so should be ok.

Really love this sight to sort out problems. Am in a regional area in Strathbogie tablelands Victoria.

Tony

hi,
A form of flow control will need to be inline on the output side of pump .
The pump needs to pulsate to some degree if not it will not keep up with the demand.
If it barely pulsates u need to consider a larger pump.
A pump with internal bypass circuit is also a benefit ,reduces the aggresion of pump pulsation .

To simplify the system ,as been said before fitting taps at the sink & shower would have been the preferred method ..
In line ball valve would be ideal on the cheap / tap with wall mount fitting for the shower

A large cheap pump is around 75 17ltr flow and a large brand name is around 100$ 11 ltr flow

swampy