'99 528i instrument problems #2

[dbell5]

2) Just the other day, the speedometer quit intermittently.
This also appears to be temp related, as it works when cold in the morning, but fails after part of the day. Today, low 50's out, it worked all the way to work and back home. I also have never had it fail while moving; I'll stop at a light, and it is dead when I start back up.
When it quits, the speedo sits at zero, and both odometers freeze.
Fuel gauge works, but all the usual damping is gone - it surges up when braking, down when accelerating, and the miles-to-empty display dithers around a lot. Both seem to average about right, though.
Although the speedometer and odometers are dead, cruise control works fine!
Does it use a different sensor, maybe one of the wheel sensors?

Any suggestions? (Other than "see your dealer", please!)
Is a system schematic available on line somewhere?

Thanks!

Dave