There is an option on the Head Unit to switch the rear pre outs from full range to sub. The HU is supposed to reset to full range. When I reconnected the battery, it was set to sub.

It's the Pioneer AVH-P3100DVD

 

haha nice i hate pioner for that reson to complicated for it own good

 

Man, see thats good to know. My Pioneer never did that but still good to know ....

 

Now ain't that a bitch !. :-)

Just curious, but just how many other brands and models of headunits also do this sort of thing of unannounced gotchas ??.