Yup. I had a similar problem with an intermittent battery rundown. It would be great for a few days, then dead. Meanwhile weird things were happening besides the rundown like seat belt lights and interior lights, etc. The repeated rundowns overworked the alternator, wrecked the OEM battery and a replacement battery before my (outstanding) dealer solved the problem. After correcting the problem the dealer gave me a yet another replacement battery at no charge since it was all linked to the problem and they had such a hard time diagnosing it. Wiring problems are notoriously difficult to find.
The problem was this: I had a bad spot in the wiring harness directly below the battery. If your battery was "covered in corrosion" that's a clue. Its a good bet some crud found its way down below to the wiring harness and continued its evil work. I can't say that's exactly where your problem is, but its a place to start looking.
My Patriot was at 190,000 miles at the time so I may be hitting problems before others with lower mileage do. Hopefully my experience will save you (and others) some time and money in diagnosing the problem. Unfortunately it was an expensive repair. The new engine harness cost about $1200 installed. An otherwise solid and healthy vehicle I figured I'd put the money into it, but it was a debate. Thankfully its been fine since and I've put 40,000 more miles on since then. Not a single repair since then -- just oil changes, that's it.
