Question

Water pump working . Will not switch off. 1992 challenger

Answer

If you have microswitches in each of your taps then it is likely that one of these has gone 'short circuit' providing a constant electrical feed to the pump. You will need to disconnect the wires to each tap in turn to identify the faulty switch. start with the kitchen sink as this tap will have had most use.
If you do not have microswitches in the taps then the problem lies with the Pressure Switch that controls the pump. This may be the Whale in-line pressure switch, our part 105500, which may be faulty of may need adjusting. Alternatively you may have the Whale water inlet with built in pressure switch, our part 127861, which may be faulty or again may simply need adjusting (screw on back).
To adjust the pressure switch, turn the adjusting screw anti-clockwise as far as possible without removing it from the housing. If the pump is still running then you will need to replace the pressure switch complete or fit a service kit that is available for both items.If the pump has stopped then open one cold tap and turn the adjusting screw clockwise until the pump starts. Close the tap and the pump should stop within about five seconds. If the pump does not stop then turn the adjusting screw anti-clockwise slowly about a half turn and the pump should stop.