relays for turn on/off power

I am trying to hook up a GPS unit in my car so that it can automatically be turned on without any user intervention. I am planning on taking the unit apart and hooking up wires to the on/off switch. Couldn't I use a relay to make the connection and simulate someone pushing the power button? I would also need to simulate the "off" action when the car is turned off. Any ideas on how to do this?

bondsman wrote: Which GPS are you trying to do this to?

I have not bought one yet and thought that it would be prudent to do some research first. I did not know that the Garmin would work this way. If that's the case then that's what I'll do (provided their new units act this same way). What I want to do is to use the GPS as a tracking device in case the car is stolen. There is software that I can add that will help me do this but I thought that I'd have to turn on/off the unit first. Apparently not. There are dedicated devices that will track your car BUT they require expensive subscription plans. I need to accomplish the same thing without the subscription. I know that I might also be able to do this with a iPhone/iPod and a program called InstaMapper.com (which is free). I'm really glad you responded :) This makes everything so much easier to do. Thanks, I appreciate it :)

Chances are the unit is not going to have a latching power switch.  Your plan will work if it does have a latching switch.  It is probably going to have a momentary pushbutton.Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

How can you track your car via a gps unit?  And for free....  please tell all..  that would be an excellent teenager monitoring device.

i am an idiot wrote: http://www.spysource.net/LASpassivetracker.htm

There is a cheaper way. GPS-Buddy has software that you can load onto any Garmin GPS unit. The cheapest that I've found so far is 19 bucks for one year of service at crutchfield. This is more of a GPS logger program though, although that's all you need if you're just tracking to see where the kids were. I cannot find how much it is to renew the service after the first year, but by then other options should be available, seeing how fast this technology is growing. You can also use InstaMapper, which is a free program, on any iPhone/iPod Touch. I am currently testing it out and it seems to work rather well. The best way to do it though from what I've researched so far is to buy a cheap pre-paid cell phone, like a Motorola i335 (they usually cost less than 40.00) and then load InstaMapper on it. When you hard wire the phone in the car it comes on/off with the key, takes a few minutes to charge up the phone, and then it starts tracking where ever your car is. It does this with no user interaction needed. I'm also looking into other options as well.

I looked up that instaMapper for my Iphone. From what I read, the application can't run in the background, so basically you have to have the app. running just to track. Stupid apple and their stupid rules. Sort of useless to me, because I just wanna know where my phone is, if it's lost.

Yeah Apple does not allow any program to run in the background, but you can still do it if you want to add several programs to the phone. This will of course void your warranty. You should look for another program called 'Private I' which tricks the person who steals your phone, and sends you an e-mail telling where they are :)

If you get Mobile-Me you can see where your iPhone is from a computer. You can also make it start making an alert sound. If someone else has the phone you can then remotely wipe the phone. Its not free, but its does a lot of other stuff too.