Gauges acting weird

The "alt gauge" (this is the ammeter) is a separate problem. Did this "just start" IE have you recently bought the car, or did it previously work? It might have been bypassed. Otherwise, the charging system is likely not working

There are several problems with gauges. If the temp gauge is pegging, unhook the sender on the engine and see if it drops back.

Could be a bad instrument regulator (IVR). This is a device in the cluster which regulates power to the temp and fuel gauge.