Ralph,

Make sense, however in this case if you read the entire thread there are times that I want the circuit live when the keys are out of the car. In a restaurant, shopping, would not be long an hour at the most and I have a monster of a battery in there. That is why the on/off switch so that I can kill juice to the plug when I don't want them "live". Say I have be charging camera batteries or my ereader and now am off somewhere taking pictures, don't need the charger running, but might need it latter so don't disconnect it.

 

For that, I'd opt for a) a SPDT switch to control; b) use a relay to actually switch the power, and c) pay attention to the wiring.

Take a line from the battery positive side; run to a fuse, then run that to the NO contact of the relay (for most of the Bosch style relays, that'll be the one labeled 87). Run from the COMMON side (usually labeled 30) and go to the positive side of the voltmeter et al.

Take one of the coil terminals (normally, say, 85) on the relay and ground it.

Take the other coil terminal (in this case, 86) and you run it to the common point of the SPDT switch.

One side of the switch goes to the battery also; the other goes to a switched 12V leg (say, the switched power to the radio.)

This way, you have "Turns off with key" and "Stays on" controlled by one switch.

(Get a On/Off/On SPDT switch, and the center will be "Off all the time"; but I'd consider that overkill.)

(The terminal numbers are the numbers on the bottom of the ubiquitous Bosch style automotive relay; that's 30A or so switched, should be plenty.)

DON'T forget to fuse the wire from the battery to the relay!

Even if you just have an on/off switch and forego letting the ignition switch control it any, I'd still use the relay; that way, you can control the outlets with a small switch where you want, instead of having to use a 30A switch to handle a 30A circuit (for instance).

Added: Before some fuss, using the NO contact for the battery side means that none of the relay'ed contacts are hot save that with no power; if you use COMMON, and use a SPDT relay, then the NC contact will have power also. This is desirable sometimes, but in this design, the isolation is ... well, theoretically safer *grins* And I'm all for "fail safe" instead of "fail deadly", especially when it's just a couple of changes to fix it.

RwP

 

Evening Ralph,

Thank you for all the help and putting up with all my questions that might seem kindergartenish.

I think I understand, run a set of wires from the battery through the hole where the radio antenna goes, that was my original plan is near where I need the power and the hole is already there. Then between the firewall and the dashboard I need a fuse. Then the strip. I have included pictures. Now the back of the 4 one is just to double check that is how the wiring should be, the voltmeter will be replaced with the on/off switch.



Fuse that will be between firewall and dashboard. Or would it be better to put it between battery and firewall in case it blows I can check it without pulling the entire dash?


Switch that will replace Voltmeter.


Wiring set up, except there will be three items in a line.

 

I'd do the fuse as close to the battery as possible; that way, as much as possible of the wiring will be covered by the fuse.

Putting it inside, if you didn't grommet it properly, you could have the wire abrade over time and short out at the firewall, becoming a nice heating element to set fire to things *grins*

So, as close to the battery as possible.

The wiring diagram will do; I'm just a bit concerned (and that's probably just my noia noia working ... ) that you might do like me, and forget to turn it off when you go away for a while.

I'd use a SPDT switch center off, one side is wired to a line controlled by the ignition switch, one constant 12V, and center is, well, off all the time. But again, that's belt/suspender type thinking, and possibly overkill.

RwP

 

Morning Ralph,

So the ring connector, fused wire, then solder that then run to the dash. When in vestigating earlier I found that was some work but I would get the wired inside the grommet that has the metal ring that the radio antenna uses, abrading was a concern of mine, had a car that that happened to and keep blowing fuses and never could figure out why until a friend of mine a big rig master mechanic took a few minutes and started at one end and with in 3 minutes found what I missed.

The on/off switch has a light so I can tell at a glance if it is on, the plugs have caps that will be closed when not in use. Truthfully besides usuing for the car vacuum, it will be used about 2-3 times a year for a cooler, so the majority of the time be off. Also if nothing is plugged in, since I am taking cooler into hotel room at night while it draw on battery, besides to light the led on the on/off switch and that would be about the same as a car alarm light in my mind.

Again thank you for all the help.

 

Well, there's the vampire draw of the USB port also; that can be significant over a few weeks.

The voltmeter can suck a bit too; I've got one I have to turn off (it's in the accessory plug so it's easy to turn off, IF I also turn off all the accessories ... ) in my Dak right now; hence the future replacement will be on the switched 12V not constant 12V line.

You can pick up some grommets from places like Amazon; I'm using some weatherproof glands myself as I add into the cab area. (A fused hot wire for the sub, a fused hot wire to feed the constant 12V lines, a switched 12V line to feed my two USB adapters I'm putting up in the headliner to run my dash cam and GPS, etc.)

RwP

 

Ralph,

No USB, no Voltmeter, I am switching those both out for cigerette style plugs to be more versitle I figure I already have a dual USB plug that is controled by the ignition in the old cigerette lighters spot. Need more I have a dual plug, but the cooler and the vacuum both need the cigarette plug.