I just found this page the other day, and I think this would be a really neat mod for the GTA. I have a question or 2 about this design, maybe a couple of you electronics gurus could help me out. Here is the page:

http://www.cvibl.com/stratus/howtos_alarmled.html

Here is this guy's circuit schematic:



I don't know the internal wiring of the DIP relay he used, and it doesn't seem like the specific model he used is available on the market today. For this reason I don't get why he wired it the way he did and his placement of the chassis ground seems suspect to me as well. To me it seems pointless to have a relay in this circuit at all (the control circuit and the load circuit are both low current). If I'm not mistaken an ignition switched +12V source is grounded when the ignition is off. Therefore, wouldn't this design suffice:

 

Well his way stops the LED from flashing when the ignition is off. You don't even have a ground on the second diagram so needless to say it won't work (unless the 12V+ on the ignition grounds itself when off).

 

His (and mine) are designed so that it only flashes when the ignition is off. I'm just making sure the ignition switched +12 is grounded when the igntion is off, and if so if my setup would work without any unwanted side effects.

 

Alright I think I see how this works. I don't think I can rely on a switched 12 for a ground. The relay seems to draw current when the car is on leaving the switch open, and then closes it when the car turns off. Thanks for the feedback.

 

You could use a normally-closed (NC) relay, and apply power to the coil through the switched 12V circuit (key-on). The switching part of the relay would break the circuit to the LED when the key is on.

 

That's what I figured.

 

Is that not exactly what I said? Check to make sure it grounds when off, because I don't see why it would.

 

I don't need to because I'm using a relay. I'm pretty sure the ignition 12 goes to an open circuit when the ignition is off instead of going to ground. It was just a matter of me misreading the relay schematic.

 

So basically you admit defeat. Thanks, I accept.

 

Let's keep it tech only, ok?

 

Another thing you can do is tap off of the lock/unlock switches so it activates when the doors are locked using a dual coil relay.

 

That's a cool idea, but my auto locks are pretty hit or miss, so I don't tend to use them. Thanks for the suggestion, but as it stands I plan on using this guys setup with a hidden switch that will cut off ground from the LED circuit and the relay solenoid to shut it off entirely.