master switch for audio?

anyone know how to wire this or possibly done something similar. i'll be installing my system in a few weeks. i've always wanted a system where u have to punch in a code to release the system to the operator or maybe even needing a thumbprint scan (i've seen these for computers for like $100).  while my system wont be very fancy, i'll have a high end hu and dont want anyone tweaking it or anything else. so i get in my car, start it, and if u hit the power on the hu nothing will happen. i would have to place my thumb on the scanner (maybe somewhere in the center console) or use a code. i have a clifford ag4 alarm w/ the coded valet switch. could i use this valet switch. how would the system know that i was punching in a code for the audio portion and not the alarm portion?  a shop did the alarm install. i'm trying to handle the small easy diy stuff.  i'm building a amp rack to sit under my rear pkg shelf. i'd eventually like to add actuators to lower the front portion down  so u can look "into" the shelf. i'd want to run this off a switch and possibly some neon. but i wouldnt want a mechanic hitting buttons and screwing stuff up, hence a master override or master on switch setup.

oh and i recently discovered this site and LOVE IT. i know nothing about electronics but i'm fascinated by it. the idea of relays and stuff is really cool. i've read the relay diagrams and i'm stil a little confused. is there a starter book about electronics i can read, possibly something leaning towards car audio/video/security.

Thats a cool idea, its a little complicated if you want to build from scratch. You could pick up one of those small kits they sell to give the system a keypad, then interface the keypad. The thumb scanner... well i really have no experience with them, but if it is USB (im assuming) you could build a circuit interfaceing the USB but the circuit would require a good bit of desgn unless someone has already designed such a beast. Very cool idea though.

Actually i was thinking while reading that since you have an alarm what about having the system disable after you open the door to get out and have it re-enable when you unset the alarm, that way when it is in vallet mode it will never re-enable... just a thought...

hmm now thats a really good idea since i put the car in valet mode for whatever servicing it gets. taking it to the extreme, i want to avoid having the car in nonvalet mode and having the car stolen then having them screw with my equipment.  my alarm also has a antijack thing too that i can activate. basically whenever the car is stopped but on, whenever a door is opened (assuming its a carjacker getting in) the blackjax activates. i have to punch in my code withing 30 seconds to override it so the alarm doesnt activate and the car shut down. i havent activated this feature yet cuz unfortunately if i'm droppping someone off, i'll have to punch in my code every time.  now i sometimes put my car into valet mode and drive it. this would leave me with no tunes. thats why i was trying to different way.    right now i have friends in the car and they change the station volume whatever. my new system will include a highend hu (i wont want my settings messed with), 2 amps, sirius radio, cd changer.  

yes i think the thumbprint scanner was a usb thing.  i want something kind of trick.  how about wiring the thumbprint thing so my thumb has to be on it while working the audio.  the one i saw allowed for a few prints so i can "approve" some of my friends into the system.  i dont do car shows or car audio shows but i'm trying to think of ways that people couldnt work my system so they can press buttons all day long and it wouldnt do anything.  i'm sure this can get complicated. but i like the valet idea. if theres a way i can override this in case i'd want to put it into valet and retain the audio.   no one drives my car but me. my friends wouldnt even think of asking. but if u let your friend borrow your car and tell them dont touch my settings, sometimes they might thinking they know how to work your equipment.  i like the idea of the audio running and needing authorization (via a code or print) for each time u want to change something.  i know this might get annoying to some. just throwing out ideas and trying to get some back.

i'm liking the valet idea more and more. even though i'd have to suck up having no audio whenever i'd put it in valet.  would i be able to multitask the alarms coded valet switch. its a two button switch.  if my code is 25, i press the right button twice then the left button to confirm then the right button five times then left once to confirm.  could i setup a relay to make it work for the alarm and for the audio separately without damaging the alarm. it cost me a ton.  or maybe the cruisecontrol buttons in a certain sequence where i disarm the car, get in, hit the sequence to release the audio system, then start the car and stereo comes on as usual and it doesnt if the sequence isnt punched in.  i want to avoid those numbered keypads. i think they would look kind of tacky.  or be able to punch in the sequence at any time so long as the car isnt going fast enough for the cruise to actually kick in, which is like 45 mph or something.  i've read mags where they use the cruise control buttons to operate major functions on radio and still retain stock functions. maybe installing a switch/relay that would use the cruise buttons for stock purpose or audio purpose.

yea i agree i think a keypad would look bad. If you dont mind a little electronics i could easily draw up a circuit that you could use 2 momentary buttons with that would require you to push a certain number of times on one followed by a different number on the other. let me know, its kind of a cool idea. You might even be able to use the same switches as the alarm, although it might be more problematic.

The thing about the thumbscanner is that i believe it allows more users due to software, unless you want to throw a PC in the car thats kind of a problem. I always thought it would be cool to have a retinal scanner behind the mirror in the rear-view, so you could stare at the mirror and the car would start... haha anyway...

Another thing i thought is you could go with the old hiding a reed switch somewhere, then pass a small magnet past the location to activate the equipment.

You will see the topics pop-up here now and then about using it as an imobilizer for vehicles.

Here is basically what it is:

You use a small switch called a reed switch that can be turned on by moving a magnet near-by.

You hide this magnet behind the dash or something somewhere.

you wave a small magnet by the location in the dash, usually people put the magnet inside an old remote transmitter,

You have some relays that keep the circuit on untill the vehicle is shut off.

 I dont know i never tried building one cause i really would rater not carry more stuff around. It would work just fine though.

Bond..........James Bond !!!!!!!!!!

Where are you going to hide the ejector seat?

My wife now hates you!  You went and put this idea in my head and I won't stop until I figure it out!

Some of the new HIGH end units come with a USB on the deck! (just a thought)

y don't u just hide a switch behind or under you dash.. thats easy accessabil to you and you only... then tap into the decks...  12volt ..... your done..  if u set the switch to off...  then ur deck/amps/subs are usesless unless the switch is set to on...  this is just a thought...

i did this for my friends probe...  i set all his electronics to a master switch.. this all started when he was pulled over and a cop decided to push his buttons on his dash and his under body neons decided to turn on and off and the cop gave him a ticked.. so he wanted an easy way to turn them off when gets pulled over....  DUMB ASS cops...

this is simply your master kill switch..

hope this helped...

  - Seven

The hu's yellow wire is for memory. Every time you cut the power to it, your hu will reset and you'll have to reprogram your settings. Instead, you could run 2 wires to your master switch, hooking one up to the factory harness's red wire and the other to the red wire coming from your hu. the 1st wire would be your power to the switch. That would make it so the hu would only be able to turn on with the key in the ign. and the switch on. With the switch off the hu would turn off, but then you wouldn't be able to listen to any music at all. Hope this helps.

As far as reading material for an intro to mobile electronics, this is one of the best websites I've seen.

https://www.eatel.net/~amptech/elecdisc/caraudio.htm

Check it out, it's helped me a lot.

I've added a switch to the remote wire and it works fine for me. The feed from the remote wire is so weak, it shouldn't damage anything.

Reuben Paul