So I bought an alpine 9883 (used, but I tested it out and everything worked). I also bought the modifry pnp harness (dci is also on the way but not here yet). I used the DIY HU install guide from here and was able to install my new HU but it does not power on. The modifry harness uses the blue harness, but not the white one for the optional cd changer. I noticed that on the stock HU when I plugged in just the blue harness the stock HU would not power on, but when I plugged in the white one it would power on. Do I need to somehow plug in the white one into my alpine deck which seemingly has no place to plug it in? Would the fact that I don't have the dci yet have anything to do with my HU not powering on? What do I need to do so that my aftermarket HU powers on?

 

Maybe someone who used the OEM power will chime in.

Alpine recommended a separate 10 amp power line and chassis ground for my 9887. You might not need the separate power line (I cut that out of my Modifry harness and crossed it over to a power wire I added) but I'll bet you still need to run a ground wire to the screw hole in the middle of the HU rear?

 

the CD changer plug shouldn't have any effect on the stock headunit
power, so here are a couple of possibilities I can think of:
1) something's loose in the main harness, and the jiggling that went
along with plugging in the changer coincidentally fixed the connection
2) the ground wire on the main harmess is bad, and you are grounding
the OEM headunit though the CD player (not sure if that's actually
possible)

 

ended up being a blown #19 radio fuse.... they had a 25 amp fuse in that spot and it was blown?