I just bought a 2004 expedition Eddie Bauer that already had a newer double din head unit installed in it but the rear door speakers, sub and amplifier aren't working. I’ve installed every after market head unit in each vehicle I’ve owned over the years and have never run into a problem as common as this in the expedition from what I’ve read up on. Has anyone has this issue and If so what was the fix/problem you had found. I’ve done some trouble shooting to the wiring and HU itself and everything is seeming to be fine. My next test is just gonna be taking out the HU that’s in there and pop in my old one I had in my 92 bronco and see what comes of that. Hopefully I get a get tips or answers to the issue before I start dismantling the dash asked center console again to further the trouble shooting of it. Thanks all for any info… Happy Expeditions to ya