'96 Dodge Caravan Infinity confusion

After reading many posts here, I'm more confused than ever! First, a little history. My wife has driven a '96 Caravan Sport for 7 years now. When we purchased it used, the previous owner mentioned that the factory stereo had been replaced because of a short. Several unremarkable years later, my wife complained of an odd rear speaker noise, and I replaced the rear 6x9s (cone tear). Her somewhat undiscerning ear didn't report any other problems until a couple of months ago, when the front right speaker started coming on/off by itself (sounded like a short and made me think back to the original problem). Later, the front left did the same thing for one day only. I pulled the unit and tried to make some sense of the harness, but quickly realized that there was an extra ground wire I didn't expect connected to the braided strap, and there didn't seem to be 4 neat pairs of wires for four speakers (one connector had 7 wires; the other had 5). Diagrams, including the one on this site referred to colors I didn't see, etc. I thought/hoped the factory fader might be going bad, so decided to take advantage of a good deal at the big box store and have a Kenwood CD/MP3 unit installed (free installation) and guess what...still no sound from the front right.

Now the questions: how do I know if this is/was an Infinity system? It has the rogue ground wire back there, but to be honest I don't know if there are speakers behind those extra grilles in the doors and back pillars or any factory amps. Next, assuming I can determine the Infinity status, how can I be certain the freebie install I got was done correctly given the odd colors and number of wires on the harnesses since the diagrams don't seem to match the factory colors. Is there a common ground for these speakers or what? Lastly, assuming all this turns out to be OK, what could be wrong with my front right? It even sounds like the front left is carrying left and right signals. I can replace the dash speakers easily enough if one or both are bad, but with all this talk of factory amps, etc., I'm concerned that speakers may not be the problem. If it helps, in the summer, the front right would start off, then come on after 5 or so minutes of driving. Eventually, it got where it wouldn't come on at all. And the day the front left quit was the coldest day for us so far, and it hasn't done it since.

Hmmmm....thanks in advance for any info or speculation and sorry for the wordiness.

I did stumble on this outstanding resource:

http://www.installdr.com/InstallDocs/DCP/PDF/327001.pdf

...and it explained the two-connector wire color mystery (why would 8 speaker wires be split almost randomly between two different connectors?...only Chrysler knows).

I'm still however confused as to why there's an extra ground wire coming from the dash with a female spade connector in a system that doesn't appear to be Infinity and, therefore, shouldn't have a factory amp. At least I have some identified wires to test now.