Dashboard dials (gas guage, speedometer) dont work.

Sounds like the body control module has gone bad. It has a relay that caries considerable current to all of these accesories and wears out.
It can also be a solder joint on the circuit board where this relay mounts.
Hope this helps, Robert

if all guages just shut off, temp, blinkers, fuel guage, etc. check for a bad ignition switch.

First check the fuse box inside the car. on the inside of the llid will be a diagram for the fuses. there is usually a fuse puller [looks like a small clothes pin] and a few spare fuses. Pull the fuse and look to make sure the element is not broken. If it is replace the fuse

My gas guage, speed odometer and tempiture does not work
The speed odometre is reading 9999999 what should i do

first check all the fuses and if they are good it may just be a bad cluster and you may have to replace it

The odometer has to be pulled out. You dont mention what year it is, but double check your fuses to be sure.

check the vehicle speed sensor located on the transmission housing.

Might be speed sensor or fuse. very strange problem, but it is probably diagnostic hint that engineered to let you know there is a particular trbl in electrical sys,.. check a manual or dealer.

My nephew has a 96 taurus also when his radio went out he noticed that his speedometer was not working as well so we check the fuses under the dashboard and found that a fuse from the radio memory was blown . We replaced it and the radio and speedometer and the odometer worked fine

I would definitely look at all of the fuses under the hood and on the left side of the fuse panel on the passenger side.