Crazy Speedometer and more!!!

[ilya79]

Lincoln LS 2000 v6

Hello,
Thanks in advance for your help in this, many mechanics have tried, we poured tons of money on this, but unfortunately the problem is still there.
Currently when I drive, all the warning lights are ON and the speedometer is at zero, no matter what the speed is. Sometimes, the speedometer "wakes up" and shows the speed, like - this morning when I was driving to work. But after you go over a speed bump it will stops working and then is off for a while and then comes back. Stability control light is on, engine check is on, hand brake and pretty much everything else. The RPMs seem to work fine though. Also, when this happens (the dead speedometer), the power steering shuts off and it is a bit difficult to steer.
Also, dry, hot weather seems to do good for it - after sitting in the sun in parking lot it seems to be better.
I don't really know where to start, or simply drive this car of a cliff - but it looks great inside and out and we are the second owner since 2001. Also, sometimes the transmission shifts are a bit hard - even at high speeds - like 40 mph. Any advice on where to start would be much appreciated.

Thank you, Ilya

PS. The trip millage and the total milage show dashes.