Hopefully I can get some direction from you folks.
I have an approximately 1990 Hot Spring spa Jetsetter serial# J-201122.
When you turn the pump on the jets surge, and after a short the main breaker pops not the GFCI(This is brand new). If you unplug the small circulation motor the surging appears to stop and the jets work great. There are new filters installed and the when the jets are running without the filters installed one of the filter holes has no suction, the other two do. A bit perplexed and I'm sure it's something simple.
I addition, it appears that after it's been off for a while and you turn on the jets the jet pump pulses, then turn off and remove filters and the pumps runs great.
Thank you very much for your time and help.