Quote: Originally Posted by vcbb5
Laidback- I still don't understand how 5v from the psu would shut the computer off when you switch off the ignition. You would have to go from an acc line or ignition line to tell the computer to shutdown (assuming your using the fake UPS idea, which i substituted with the com 4, com 8 short idea in my latest plan).
I'm not sure how I can explain it any simpler!
UPS service needs 5v on pin 8
Take 5v away from pin 8 and computer shuts down. Simple!
Once again, it doesn't matter where the 5v comes from, PSU, a battery on the passenger seat or a wind generator on the roof!!
Maybe you forgot, I use a relay controlled by the IGN wire.
IGN on = 5v to pin 8 = computer stays on
IGN off = 0v to pin 8 = computer shuts down