Arrived onsite and was shown to the main electrical panel and where the hot tub hooks up to. It runs outside to an older spa disconnect which the hot tub tech reportedly told the resident, the breaker is bad so call us to have it replaced. I started by testing the power at the hot tub disconnect and testing continuity to all the hot tub wires going out to the tub. I found resistance between the ground and neutral with other conductors while the tub was hooked up. I was told the hot tub tech came out, replaced the heater, and then said it wont work because of the breaker. For testing purposes I replaced the breaker with a standard and tested to see if there was any voltage bleeding onto the ground or neutral, and it was mainly on the ground. I then proceeded to have the resident open the front panel of the hot tub so I could take a look inside and test further. Upon inspection i found the terminal block for the line side wires coming in from the spa disconnect, was very loose and the sc