[H3 Hummer 64]

I pretty had same problem. The whole bit with the clock and everything. My problem ended up being loose battery connections. I started having the problem after I installed a set of PIAAs. The battery connections are a pretty stupid design. Its a special nutt that has to go down into the hole to actually get the connection to tighten on the battery post. Since I hooked the lights to the battery I now had the connectors for them inbetween the nutt and the hole at the base of the screw. So the battery connections never got really tight and you could wiggle them. Once I re-wired the lights and put the battery connections back to the way they were everything has been fine. Hope that makes sense, if it doesnt look at the nutt and the battery posts.