Originally Posted by nox1s
When it is in the "run" position, it's getting power.. so you can turn the radio on when it's in "run"... that seems like a good thing to me
If you were looking for power for the head unit sure it would be a good thing. But he's looking for the signal to tell the GPS unit when the car is put in reverse. The lead he is looking at is always "hot" so it won't work for detecting reverse.