when I,m driving my speedo jumps around it stays constant most of the time but when I turn on the auto temp control it says 0 when I let off the gas.

Can you read the speedo input on the diagnostic display (through climate control diagnostics)? Or is there diags on that model?

My 94 it is pointer 14. I forget on my 91 SDV, but it read it too.

If the speed sensor is bad, TCC lockup will be wrong, is it working ok or not? It should lockup around 40-45 mph.

it know says 0 all the time just started that about 6 hours ago.I don'tknow if mine has diags on it or not. I'll look in my manual to see. Oh! when I hit big bumps it has some read out but not stedy.Some times it works at take of but this all happened today.I got a speed senser today,but its too dark to change.thanks for the help.I'll let you know if it works.

What about the rest of the dash? Do the odometer and trip odometer work alright or do you get messed up numbers?

they are all good. except the mileage it has always been a little dim. but the trip meter hasn't moved since the speedo stayed at 0

I changed it today it worked. but I think I have an electrical problem in the wires. at first it didn't work,untill I shook the wires a little.

Sounds like a loose connection or bad ground in that case. Good luck.