Just installed new pressure switch. New to wells and pumps. Attempting to fill waterbed and pressure will go from 80lbs to 40lbs leaving me no pressure at all. Help

Need a little clarification.

First of all, 40# is pretty good pressure, so I'm not sure what you mean with "leaving me no pressure at all".

Secondly, 80# is really high. That is controlled by the switch. Every switch I have heard of is rated by the cutin/cutoff pressures, such as a 30/50 switch. Never heard of one with a cutoff of 80, so how are you getting pressure that high?

At any rate, well pressure is controlled by the switch. You can adjust that by turning the large, center nut under the grey housing (with power off). Turn clockwise a full turn to turn pressure up, or ccw to turn pressure down. Then turn the power back on and see what you have by cycling the pump. Keep adjusting until you get what you want.