Since I JUST dealt with this today, I thought I would continue to build this old thread :-)
My battery died in the parking lot of a Les Schwab while I was checking out some 33's (I ended up not buying yet) but I Figured since my jeep came with a battery that looked fit for a lawn tractor, I sucked it up and bought a real truck battery for $55.
I just got back from a 1 week vacation and my battery was totally dead.
As I started looking for what could be draining my battery that wasn't before, I remembered that the Horn relay stopped "clicking" when I pushed it (my horn doesn't work so no big deal, will fix it later)
Remembering this, I removed the steering wheel cap and debated whether I should pull it all apart I noticed a small metal shaving shorting out the horn ring to the wheel nut.
I brushed it away with my fingertip, and relay now clicks again, problem solved.
Easiest/cheapest repair ever!
1980 CJ7 - The Grenade