I have looked and searched and found nothing like my weird problem, so if this is a duplicate question, I'm terribly sorry. But here goes.
I have a 93 EX, auto trans. When I bought the car the gas guage was always on full and my cruise control wouldnt set, the button on dash turns on, but nothing happens when you "set" it. So I don't know if those problems are related or seperate but eh, the main problem I'm having is my speedometer randomly drops to 0. It will sometimes flutter up and down then start working, and sometimes it will just drop to 0 and my check engine light comes on. When it stops working and my check engine light comes on, my tripometer and odometer stop working. But usually after a few min, it will all start working again. My tach and temp guages still work though when it drops to 0. When my speedometer "flutters", the trip and odometer still work... Any ideas? Nothing else seems wrong, no other lights or malfunctions. When I turn my car off then turn it back on, my check engine light goes off and my speedometer will work again for a few miles, then it starts all over again. Once it does drop to 0 and starts working it again it will stay working for the rest of the ride. It's weird. Thanks guys. =)

 

Take the car to Autozone or your local equivalent and see what the CEL (check engine light) code is. That might tell us something. Even though the light is off, there is likely a code stored in the computer.

I would assume the VSS (vehicle speed sensor) is intermittently bad or the speedometer itself is going bad. A CEL code might point to the VSS.

As for your gas gauge issue, I had the same problem on my old 92 EX. It was the fuel sending unit. It's basically a float switch that's inside the gas tank. I had mine replaced and the gauge worked fine. (It was never really that accurate though.)

The cruise control issue could be a few things, but since cruise relies on vacuum to run, I would look at the vacuum lines and see if one is disconnected. If all lines are fine, the unit itself might not be getting power (though the switch works). I'm not sure if the cruise control wouldn't work if the speed sensing parts were not working. It's possible that they are connected though.

 

On a 93 you can read the code yourself with a jumper wire. Autozone doesn't mess with OBD1 cars, they only know OBDII which started in 1996. It probably is the VSS. Unplug the VSS and make sure the plug is not loose or corroded. The VSS is located on top of the transmission at the back, above where the two CV axles come into it.

For the gas gauge take the bottom cushion of the back seat out and unplug the wires that go to the top of the gas tank. The gauge needle should now go to empty when you turn the key on. If it does that, it's going be the sender in the tank like Hobo said. If it stays at full it's probably the gauge itself in the cluster.