Thread: Switch w/ opus question

Originally Posted by Mears

Ok, I'm wondering if this is possible. I was thinking that in addition to running the ignition wire to the 12V sensing input on my Opus, I would also split the power wire running from my battery so that it also connects into the opus sensing input. At this point, my opus would always run, but what I'd like to do is wire a switch so that it can open and close the spliced wire that feeds off my power wire. This way when my car is turned off I would just push a button or flip a switch to close the spliced wire so the opus still senses 12V.

Assuming the above is possible, can I use any type of button for this or will I need a switch type? Lastly, is there any place that shows how to wire a 12V switch?

Check this thread.

The same principle applies for your situation. A DPDT center-off switch that alternately connects the ACC input to the ignition or +12V (or nothing when in the off position) will allow you to start the system with ignition off (or keep it alive when you turn off the ignition), prevent the system from starting when you turn the ignition on, or have it behave normally in synchrony with the ignition.

Sweet. I think I'll just pick up a 3-way at autozone or Radio Shack.

Couple other things. The thread you linked had links to AC switches. Is there any reason they wouldn't work in a DC circuit? Lastly, where is the best place to get constant 12V? From power wire, cig lighter, fuse box, etc.

Originally Posted by Mears

Sweet. I think I'll just pick up a 3-way at autozone or Radio Shack.

Couple other things. The thread you linked had links to AC switches. Is there any reason they wouldn't work in a DC circuit? Lastly, where is the best place to get constant 12V? From power wire, cig lighter, fuse box, etc.

The switches are fine. The ratings are relatively unimportant in this case since the ACC input sinks ~10 milliamps at most.

The battery input should be fed from - the battery.

Use a fuse block at the battery post (the fuse is to protect the wiring in case it shorts somewhere between the battery and the Opus). Use a 10A or 15A fuse.

yeah, I have that half completed myself - three way switch , but right now only the acc power is hooked up - still need to run a 12v line from constant power to the other "on" position of the switch...

You just inspired me to get off my *** and do that this evening...

Originally Posted by STI_FFY

The switches are fine. The ratings are relatively unimportant in this case since the ACC input sinks ~10 milliamps at most.

The battery input should be fed from - the battery.

Use a fuse block at the battery post (the fuse is to protect the wiring in case it shorts somewhere between the battery and the Opus). Use a 10A or 15A fuse.

What I meant is which constant 12V source should I use to wire into the switch. Running all the way back from the battery seems overkill I was thinking of either splicing the cigarette lighter or the power wire I have running to the opus.


Also, I just thought of a cool idea. You could wire the output from the switch so that it also goes into the chimer that your headlights do.

Originally Posted by Mears

What I meant is which constant 12V source should I use to wire into the switch. Running all the way back from the battery seems overkill I was thinking of either splicing the cigarette lighter or the power wire I have running to the opus.

You could certainly do this, but don't use the cigarette lighter and computer at the same time.

...and make sure the cigarette lighter socket does not go dead when the ignition is off.

Why would I not be able to use both at the same time?

Current draw, my friend!

The wires connecting your ciggie lighter arent rated for large currents - - - use both at the same time, and if you're lucky, you'll blow a fuse - - if you're unlucky, you'll get the unmistakable smell of burning wire