Yesterday I ran the battery down trying to start my '88 535i in the morning when it was cold and did not want to run. That afternoon, I jump it from another car and after a few minutes she fired right up. However, now my radio, tach [along with several other gauges] windows and a few other things are not working. My locks, and lights, however, still work fine. I checked all the fuses, and all are good. Any ideas what this might be or what I might try to fix this problem?