1999 740iL Speedometer, Odometer inop (and ABS light on)

Hi,

I have a 1999 740iL. The speedometer, odometer, and instantaneous mileage indicator are inoperative most of the time. Also, the yellow ABS indicator (and another yellow light) on the dash are also lit whenever the gauges are not working.

The ONLY time that the gauges work is when the temperature is under about 45 F, and if the car is cold. If the car warms up, or if the temperature outside warms up, the indicator lights go on and the gauges don't work.

I presume that there is some faulty connection that works when the parts are cold (contracted), and bad when the parts are warm (some degree of compression due to thermal expansion).

Any ideas??? (One fellow said that this could be either an internal fault in the instrument cluster, internal fault in the ABS module, or faulty wheel speed sensor).

What makes the most sense, especially given the thermal nature of the problem??

thanks

Do not rule out the ignition switch (not where the key fits but a contact/insulator setup accessible via the left side of the steering column). they get old and mix signals to the various electrical functions. Not too expensive aftermarket. Instructions on youtube.