Installing Aftermarket HU 03 Navigator w CD6

I recently bought a 2003 Navigator for my work truck and so far LOVE it,although there's not a whole lot of info in the various forums that cover the Navigators, either they're Expedition/Navi forums or Navi/Aviator forums for the most part and I've had a HECK of a time finding just a few simple answers to a few questions I've got as I REALLY want to swap the factory CD6 head unit (so no factory NAV, no rear seat DVD, as that seems to come up in the various fit guides as a question) The ONLY real info I was able to find anywhere was here in "The 12volt", where I found a couple of wiring diagrams for 03 and 04 Navigators (like reading Greek to me, sorry!) and one question which seemed to jive with what I've learned about the various harnesses you can get for swapping in an aftermarket HU for the factory CD6 unit. My main reasons for swapping-aux in of course at the very least and for a few $$ more I can various other controls when connecting my android phone to the new aftermarket units. Plus, I NEVER play CD'S anymore, so couldn't care less if its a CD6 OR CD600! Now, as I understand it and was confirmed by the ONE post I found on here is that the CD6 unit like I have (which as far as sound quality goes, sounds just fine to me)is that there is a factory amp that powers the factory sub on back area on drivers side and the rest of the speakers (in each of the four doors) are powered directly from the factory HU. Does anyone know how much power comes from the factory CD6 HU to power each of the four door speakers and what ohm rating the factory door speakers are? I'm looking at aftermarket HU's with the 22 watts RMS x4 power output to the (4) door speakers, which looks to be the most you can get without adding an external amp, which just isn't in the budget right now. Would this be enough to power the factory door speakers that are in there now, or would I be coming up short? Also, just making sure the factory door speakers are 4 ohm speakers as well, so I don't blow up the the amp in the HU. I would be getting a HU with 6 pre-outs, so IF budget and time permit down the road, maybe I could install some new, higher quality door speakers, but for now if I can simply add the new HU with the aux in, bluetooth, etc and have the same quality sound as I get now from the CD6, I'd be happy as heck! Thanks in advance for your help!

Speakers are 4 ohms. If it has a factory subwoofer purchase a Metra 70-5521. If it does not have a factory Sub, purchase a Metra 70-5520 The kit you need is a Metra 99-5026 if you are putting a single din unit. If Double Din a 95-5026

Thanks a lot for the response and the confirmation that the door speakers are 4 ohms and I DO have the factory sub with factory amp and was going single din, looking at probably a Kenwood KMM-BT515HD, has all the features I want, no need for a CD player in a decade, has the HD tuner which for the times I listen to the radio is great, (6) 4V pre-outs in case I do get the car audio bug again and start ordering amps and new speakers, etc and the Metra 70-5521 looks like the harness to get! One question still, does anyone know how much power the Ford CD6 head unit was putting out to those (4) door speakers? Another reason I like this Kenwood KMM-BT515HD is that it puts out the 22 watts x4 RMS that seems to be the max you can get from any of the aftermarket HU's I've seen. I just want to make sure the Ford CD6 unit wasn't somehow pushing more power to those door speakers and that I'd be losing out on the power to the door speakers by installing this HU, with the 22 watts RMS x4??

The OEM radio gets power from the same 12 volt source. Mathematically speaking your OEM radio and your new kenwood radio puts out 17.5 watts per channel. Look at specs on Alpine radios. They are the ONLY ones that are honest about the output of their decks. They claim 18 watts per channel. Some new radios (That have an actual switching power supply) do claim and deliver more than 22, but they do have a power supply in them. Sony has some. They are easily identified, they have larger power and ground connections.

I have the factory door speakers in my 02 Mountaineer and currently running a Sony 600w amp (150w x 4)to power them( the speakers on the backside say 4ohm and 25watts).   I don't have it cranked up to the max that the amp will push, maybe half and the speakers haven't given me any issues so far and it's been over 6mo. I also bypassed the factory sub and installed 2 12's, now I actually have bass I can hear/feel.