latching master relay wiring

i am an idiot wrote: The above diagram will change state everytime you push switch to the left.  If it is on, and you push the switch either direction, it will turn off.  If it is off and you push switch to right, it will do nothing.

Yes, that is exactly what I said. I want to add/convert whatever to make the switch do nothing when pushed to the left (ON) when it is already on.

I can not think of any way to do that without having a relay powered up while the solenoid has output. 

i am an idiot wrote: I can not think of any way to do that without having a relay powered up while the solenoid has output.

Like this, right? It seems like there would be a good way to do this with a latching relay so it would not take power to maintain, but I haven't figured it out.

Your solenoid is latching.  Is it that hard to see if it is on before you try to turn it on?  Have you thought about an LED indicator?  Minimal current draw when it is on.

Your above diagram should do the trick.

i am an idiot wrote: Your solenoid is latching.  Is it that hard to see if it is on before you try to turn it on?  Have you thought about an LED indicator?  Minimal current draw when it is on. Your above diagram should do the trick.

It is in a locked box in the trunk with the battery. The car has been shaved and I am going to use the unlock functions to pop the doors, and I wanted to be able to use the arm/disarm alarm outputs to turn the main power on and off. So I don't want to hit the arm button and have it turn on, or vice versa. It would also not be very convenient to have to check the state before you turn it on or off.

I think this will work, it only grounds the coil of the relay when the momentary switch s pressed. I don't know if the changeover from one terminal to the other will be a problem.

I take it that the latcher is a pulse type - ie, each +12V pulse swaps its state - as opposed to one that requires a coil polarity change. In that case it is simply a push-button to swap. No relays except if it is an alarm etc to enable it. (The alarm being ties to battery +12V hence always presenting a drain irrespective of the latcher. Doesn't that contradict your aim?) Connections from the relay's output seem meaningless.

oldspark wrote: I take it that the latcher is a pulse type - ie, each +12V pulse swaps its state - as opposed to one that requires a coil polarity change. In that case it is simply a push-button to swap. No relays except if it is an alarm etc to enable it. (The alarm being ties to battery +12V hence always presenting a drain irrespective of the latcher. Doesn't that contradict your aim?) Connections from the relay's output seem meaningless.

1. Yes, it is a simple pulse, polarity does not matter. 2. I am ok with the alarm draining the battery, as nothing else will be on at that time, and they are designed with that in mind. What I was trying to avoid was having the relay draining power when I don't turn the main power off while the car is parked in the garage, or any other place I park, or if I forget to set the alarm/cut off the power. 3. The relay's single output would only connect to the master relay if the power is not already on, and you push the switch to on. Any other combinations are ignored by the relay.

To further illustrate #3 in the previous post: When you push the switch to the left (on) position while the relay is not energized, the power would travel from M1, to the NC terminal on the relay, out the common terminal to the switch, and through the switch to T1 on the master solenoid. If the relay becomes energized due to there being +12v at M2 and the switch grounding the other side of the coil, the relay would be connected across the NO terminal, and nothing would happen.

So it is for short term storage as well as long. (Physical isolation switches are best for long term; they handle the starter current as well.) IMO it's the wrong relay for the purpose. You should have a dual-coil latcher, else a polarity changer (but that requires an extra relay in your case). And lest hope it doesn't release whilst driving.