Pump shuts off on low, doesn't run at all on high.

I just bought a used LA Spa and need some help. It is 6 years old with air button control, 240V. Here is the issue: When I flip the breaker to turn it on, the pump will run on low speed for about 90 seconds then the relay will trip and it will shut down. A couple of minutes later it will come on and do the same thing again. If you try to turn the pump to high speed, it just shuts down. The blower and the lights both work fine. Also, when the pump shuts down there is a visible spark from the relay. I replaced one wire that was disinigrated from the relay to the heater. I have attached a couple of picks to show the pack. Any help would be appreciated. Thank You.