My rpm and mph it stop working I need help finding the fuse

Checking your fuses should be the first thing. If that doesn't help, grab a voltage reader and start checking all wires until you find one or more that show no voltage. Then check these wires to see if an animal has been chewing on them. Be sure to check for any breaks or over heated spots. Sometimes wires can come in contact with hot metal. You might have to change out a few connections. I drive a Dodge Caliber and my entire dash board went out and the lights wouldn't work. Since I had less than 30,000 miles on the car, I took it back to the deal several times. Took months and changing out wiring and rechecking the computer but they finally found the problem. Might want to see if someone can check the computer too. Had a Buick once that kept shutting off. They changed out just about everything on the computer before finding it. Good luck and hope you find your problem soon.

there should be a torque converter clutch servo/solenoid and it is controlled by a sensor
run the fault codes first

tire size or gearin.

check fuses

Google : Dodge cluster solder, in google images. Or have a look at earlier posting by another Fixya expert.

http://www.fixya.com/cars/t6439654-99_dodge_caravan

for both gauges not working it must be the circuitry behind the cluster. A qualified technician will need to look at this

try to reset the computer if that doesnt work reset the idle speed it may have picked up bad codes

It's hard for me to understand all of what you said, but I'd start with checking all of my fuses. Look for a blown fuse. Replace. If it blows again, you have a short somewhere.

check the RED 10Amp fuse No17 located at the glove compartment fusebox

your in limp mode have the vehicle scanned for trouble codes most auto stores offer this service for free --