Here's my story. I have a Sundance Marin spa, 2001 build year. It has been empty for a few years and recently I decided to get it going again. I filled it up and everything seemed fine except the 2 speed pump that circulates in low and runs jets in high. The seals wore out and it started leaking. I decided to replace the pump completely because the motor shaft was old and rusty/corroded.
I installed the new motor, exact replacement and wired it up correctly making sure the red/white/black/green went in the exact same spots and I verified it with the install diagram and photo of the old pump. I filled up the tub and it up and let it circulate for a little while. Then I put it on the second speed of the motor for about 10 minutes, maybe less. The next thing that happened was that the circuit breaker tripped in the house panel. I thought that was strange so I checked a few things and the motor was quite hot to the touch. I decided to let it cool and it took a while for it to cool. After that I flipped the circuit breaker switch and it blew again right away. This time the main fuse on the spa circuit board blew as well.
I replaced the fuse and flipped the breaker switch again on the fuse box and the spa began to work in circulating mode again with no issues. When I put the pump on the second speed for the jets now, you can hear the relay click and the motor kick into high and then the motor shuts down after a second or two. The spa jet switch discontinues to work - off/low/high. If I cycle the power at the circuit breaker switch, the spa will start like normal and start the pump back up in low (circulating/heating cycle). Hit the off/low/high switch, same thing happens. I disconnected the new motor and reconnected the old motor and the exact same thing happens with the old motor too, possibly eliminating the issue at the motor. I'm thinking something is up with the relays on the circuit board. Is there a way to test or verify this? Any other thoughts on what else it might be?