I need a little help w/88 m-5 odometer, it is now recording exactly 50% of the milage traveled. The speedometer works fine though. In maybe a related problem, the on board computer works fine for outdoor temp, time, day and date, but will not display speed, miles per gallon, or fuel left. Are these related and where do I start? I'm sure there will be many more questions coming as I start to sort out this car. Thank for the help.