Oh holy SH*T!!
REDBULL - thanks for that last wiring diagram I've never ever seen anywhere!!
So - that is where that 2 amp fuse is, and where that black / yellow wire was tapped as a split and was blown. I kept wondering why it was blown, now I think I know.
Must be grounding to frame in either the A Pillar or roof area that darn green wire.

(now as to theory, why oh why, is a auto dimming rearview mirror tied into a back up light circuit?? And could wiring diagram authors have been a little more explicit instead of writing 'option connector'? How could I know that's there casually looking? I'd have to have access to that last diagram you provided.)

 

My memory is a little fuzzy right now; but, if i remember correctly, when you put the car in reverse, the auto-dimming feature may be turned off or something like that. There was a discussion on another forum before, where people were trying to tie into those wires to power other aftermarket electronics and it was mentioned that in reverse, it won't receive power on a certain wire.

 

I was thinking, maybe it is circuited that way to override the nighttime or bright light in rearview sensor and provide Maximum rearward brightness vision in the mirror itself when in fact, backing up.

Also, I have a bad feeling I'm going to have to wrap this up with a "there, I fixed it" confession. I will confirm tonight if what I did on Friday June 7th did all of this.

 

Problem solved. Thanks to all the help on this forum!!
And especially thanks to RedBull for the final help and missing electrical wiring diagram.

So the, uh, problem was something, uh, I did.
"There, I fixed it" was basically what I said in June when I found a new bolt to replace a missing head visor bolt. I was being careful but somehow I managed to pinch the black - yellow and green wire four pack to the auto dimming mirror.
The wires were jammed and crimped by the metal attachment point of the visor and just barely cut a wire strand width from the green wire sheathing. The green wire was shorting right there and took out my whole back up light circuit.
I'll post a pic tonight of what it did. It was somewhat minor but big enough to give me headaches and fits for 2 months.

 

Glad to hear it finally was fixed, this thread was getting very long without resolution. Yes, please post the picture.

 

Here's the pics. The four wires got wedged between visor mount. 4 wires crimped a bit 2 with very slight tear thru the insulation. I pulled wires out of headliner cut and pulled back the black sheathing and then electrical taped the wires to insulate them as they are. Now I can go into reverse!

 

Dang.......you found it. Nice job

 

Thanks Pooman! This was quite the nutty repair for me. I really wished I remembered I tightened up that sun visor that day... could have saved me 10 + days of work.

(I remember seeing the wires there, and trying to make sure they would not get hit by the bolt, they didn't, but got pinched by visor mount instead. I watched the area for any sparks / smoke in case I struck a hidden wire and then completely forgot all about it when nothing happened).

 

I just want to thank you all for the many hours of work diagnosing this issue. I had a similar problem with my '05 EX-V6 and it was making me crazy. I spent hours diagnosing the obvious added iphone connection, back up lights, etc, etc. Then, by the grace of God, I found this thread. I read the first few pages early on in my experiment, but yesterday I finally read through to the end. Well, don't you know I had my headliner replaced after moving to Florida last year (Florida killed my AC and my headliner instantly, thank you very much). I am the original owner, so I know everything that has been done to the car. Of course, I completely forgot about the headliner until I read this. In any case, I pulled the harness out for the auto-dimming rear view mirror and, voila!, bare wire is exposed!!

Where may I ship the case of beer?

 

Haha!!!!

Thanks man.

You know what, I have a huge grin here. I am thrilled if it helped someone else.
I mean, I was almost pulling my own hair out on this one.

Excellent news you stumbled on this thread and it helped you! Congrats on the diagnosis and fix!