Have just installed a 'new' Instrument cluster into my 89 740 non-turbo (used to be wifemobile, but it has been replaced by an '09 Honda civic, but I'm keeping it). It shows 98000 miles on it and I don't have to bang on top of the dashboard to get the fuel gauge and voltmeter to work. Still, the odometer just stopped working this morning when I zeroed it out.
Is this a mechanical problem (like the 240's) or an electrical problem, like the 700 FAQ?
I have several other spare clusters on hand to take out various spare gears, etc. So, what should I do??
Thanks,
el raidman

The odometer in my 89 740 turbo stopped when I pressed the trip odometer reset the other day at the beginning of a road trip. Then, about 15 miles later, I went over a bump on the freeway (construction) and it started itself up again. It was the most absurd thing.

If the speedometer is fine and only the odometer is out, the problem is most likely mechanical. I sifted through a bunch of old posts on here and found some suggestions that the reset button jams the odometer gears on the older instrument clusters.