No circulation

My husband bought an old used hot tub earlier this year. Had an electrician friend wire it up and once we cleaned it out and turned it on, we thought we were good to go. But although the lights came on and the water heated, some of the jets didn't work. That was okay. (The tub is a 5 seater and there's only 2 of us. We didn't "need" them working.) My husband used it every day for a couple of weeks and then it stopped working. We never "turned it off", we just turned the thermostat down and turned the jets off. We left it circulating all the time. (Don't ask what our electric bill looked like!) Then one day it stopped heating. The circulator didn't sound right at that point. Turned off the disconnect, turned it back on and nothing happened. Nothing would come on. Main breaker would trip. (Not circuit board / GFCI, breaker at the disconnect/main panel.) My husband started disconnecting components until the breaker stopped tripping. Got to the "ozone" component and then it started working, partially. The jets will come on and so will the heater but once the jets are off there is no circulation. I apologize but I don't know much about hot tubs. I do know that has air control and the older style air blower. Any idea what's wrong?