My daughters' 1989 240 has a dashboard with a mind of its'own. It started out with the fuel & temp guages becoming intermittent, then the warning lights were intermittent.She says whacking the top of the dash helped for a while...Now the alternator has gone out so I'm tackling multiple problems. The rebuilt alternator is not charging the battery. I took the instrument panel out & did the procedure for tightening the contacts on the temp compensator board & reseated it. I replaced all fuses & cleaned every contact I could find. Although perhaps not related, the speedometer has quit also.The clock, dash & exterior lights are working. The row of warning lights does not come on when the key is turned on. Another interesting item is the "bulb out" light not working; to test I put a known bad bulb in one of the taillights.
Am I chasing a bad wiring harness or just a bad ground connection I haven't found yet ? And to add insult to injury, IT STARTS AND RUNS JUST FINE...