I have a 84 240 (230 k miles) with electrical problem. About three weeks ago car just killed in traffic. Ignition lights on, would crank, but not start. While waiting for tow, cranked a few times, sometimes ignition lights did not come on, but would still crank. After towed home the car started up. I cleaned all the leads ran it several times on the driveway. Then took it on the street, ran a bunch of errands just fine, then killed again(shortly after I went over a dip in the street). I turned the key, got ignition lights, car started, got another couple hundred yards or so and then killed again, this time no ignition lights on dash, cranked but would not start. Pushed it out of traffic and around a corner. Turned key, ignition lights came on and started, headed back toward home, stalled again, this time cranked but no ignition lights and would not start. Towed home, ignition lights back and car started. With the car running I tried jiggling wires under hood and under dash to see if there is a bad connection, no luck. Several years back I replaced the main wiring harness, but not the stuff under the dash. Any advice?