Installed a new headunit (pioneer avh-p2400bt) a while back, and it works almost flawlessly.
I have a backup camera installed on the rear bumper under the spare (ugly when tailgate is open, but pretty concealed when it's closed). And it turns on automatically when the reverse is engaged because I tapped into the reverse light output.
BUT, when using the PAC C2R-CHY4 wiring harness, the headunit doesn't switch automatically. I'm 99.99% sure I'm using the correct wire.
When I test the wire with my voltmeter, it's at a constant ~11.4V regardless of reverse gear or not (batter is around 12.5V at this point, so may be some high resistance load with some current somewhere...).
Any ideas? I can get into review mode manually, but it'd be nice for it to just work when I switch to reverse.
Thanks for any help