Originally Posted by vcbb5
I'm not sure how I can explain it any simpler! :D
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