Odd Speedo Problem

ok so the other day Im driving and my speedometer decided to crap out on me. When this happened my gas guage and coolant guage shot up so I couldn't really tell how hot the car was or how much gas was in it. Then the next day none of it worked. So I read the forums before posting....We soldered the board that didn't help....Then we went out and got a new cluster. Installed it and everything works (I think) but the speedometer. There are no shorts we can find nor is the fuse gone. So whatelse do we need to check? My husband is a bit challenged when it comes to fixing cars so anything you can provide detailed would be great

did you solder the new cluster

there really isn't any need to solder the new cluster it worked in the car I took it out of. I hardly think there is a problem with the board I think there is a problem somewhere else I just need some sort of direction

If the problem isnt with the soldered connectors on the cluster, the next most likely culprit would be a Vehicle Speed Sensor, that was bad, or had come disconnected, or worked its way up out of the tranny. This VSS is located at the back of the tranny, on the upper side, close to where the passenger side axle shaft comes out. Its not easy to reach, can best be seen by looking up from underneath.
The usual speedo/gauge misbehavior is due to the connectors pins needing to be re-soldered. And the same connectors provide the signals to the fuel gague and temp gauge. Thats why you got those suggestions first. The VSS failure problem is not so common - as well as more work to deal with. It also wont affect the temp gauge or fuel gauge. A bad connection to the cluster (ground or 12 volts) will affect them.
Be sure all of the ground connections under the hood are intact. There are several of them, and they are all important. There is one ground wire running to the front of the engine compartment, bolted to the radiator cross-member. Its a small wire, but seems to carry a fair amount of current sometimes.