Engine Disable via Stereo System...hmmm?

[LCD Gauges]

On my drive home tonight I was thinking about the GTM, and the final interior considerations. I've ordered a fairly elaborate stereo head unit
which should arrive tomorrow afternoon.

With this stereo is a detachable face, with a touchscreen which can utilize a pass code to lock out certain features - an ISIS of sorts? As the
gears turned on my journey, a light suddenly tripped on; why not use one of the outputs of the head unit to power relays that will enable starter
solenoid, coils, fuel pump, injectors, etc.?

The possibilities are endless if you're handy with wires, and relays. Of course, I don't want to elaborate on a public forum, but use this example
for a basic security feature:

The trigger lead from the stereo head unit that enables the amplifier can be shared in parallel with a relay that is Normally Open (N.O.). When
you power the head unit, it sends 12 volts to the relay to close the solenoid circuit.

You can couple this with an existing alarm system, and/or run multiple relays to kill several circuits. It would make it very difficult for someone
to get the engine running without knowing the layout. In certain cases, you may need to build/find/buy a hold-latch (flip-flop) circuit to maintain
critical systems such as ignition, and fuel in case you switched off the stereo while driving. :D

Also be mindful of how many devices are powered from one output as the current capability of the head unit is limited. A current amplifier may be
needed.

Alright, I had to get that off of my chest before bed. Maybe I'll sleep on it, and think it's all a bad idea. That quick release steering wheel is looking
like a good idea too! OK enough, I'm going to bed.

[VRaptor SpeedWorks, LLC]

My only comment:

Increased complexity = decreased reliability. Every component you add into an electrical circuit is one more point of potential failure and one more source of resistance/voltage drop in the system.

[crash]

I have done this many times. Usually there is a primary lead on the starter solenoid or solenoid relay that is relatively low voltage. I put a 40A relay inline there and have it controlled by a number of different items. For instance, sometimes the A/C must be on and set to full cold for the starter to work. Sometimes it is tied into the radio. Sometimes there is a switch, etc, etc. I make it something very easy to bypass should the relay or whatever fail. Again, if someone is determined to steal your car, they will show up with a flat bed truck and haul it off. That's when the GPS tracker is useful. ;)

[WIS89]

I actually like your idea, but with a small dose of what Shane has added. In other words, rather than disabling so many different components via the head unit, just pick a single or perhaps two components which can be disabled with the removal of the head unit.

This would lessen the complexity--with a nod towards Shane's valid concern, while still accomplishing the extra security which you seek. It's kind of elegant actually, and I think so out of the norm to make it rather effective. I think you have a clever idea.

Regards,

Steve

[LCD Gauges]

Yes Mike, it's true what they say, "locks are for honest people". Just throwing out some ideas for those without an ISIS.

As for doing "all" of the kill features, that wouldn't be practical, or necessary for the reasons Shane, and Steve stated.
The possibilities listed in my first post were options available that will work effectively to delay someone from starting
the engine.

The scenario played out in the basic example would be plenty if done properly.

Rock on everyone. :cool: