Is this ok?
(see attacked picture)
Building a shutdown controller / relay board
Here's what I want it to do...
Basicly, when the car's off, it board would be off as there'd be no power on the switched line, and the relay on the constant 12V will be open.
when the car goes on, the switched line goes hot, and the board powers up, the pic microcontroller then activates the relay on the 12V constant line . The idea is, that when you turn your car off the board still get's power, and will be able to do it's work, (turning off computer etc) before finally turning off the relay giving it power, shutting it all down...
I'm 99% sure this setup will work, but then again I'm a bit of an electrical noob, and would rather not F-up my truck. I added the diodes so that the two seperate power lines wouldn't "bridge" (ie, 12V constant givng power to the switched after the switched went off) but am not entirely sure that's all I have to do...
Thanks for the help