Spa 2 speed pump issue, relays?

[nmasino]

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?

 

[Bama Rambler]

Have you checked the wiring to see if the insulation was cracked. Sitting for a while may have embrittled them and when you moved them around rewiring the motor they could have shorted.

 

[nmasino]

I checked the wires for any cracking or fraying. I did notice a hole in the black wire for low speed and taped it up but that didn't change a thing. To verify that the wires aren't the issue I ran these tests.

1.) Disconnect the high wire from the circuit board and run just low speed. Worked fine.
2.) Disconnect the low wire from the circuit board and run just high speed. Worked fine, the relay cycled to the second speed just fine.
3.) Disconnect the high wire at both ends and substitute it with another wire that isn't in the harness to verify there isn't a short inside the harness. Both low/high hooked up - same outcome - high speed kicks off after a second or two
4.) Disconnect the low wire at both ends and substitute it with another wire that isn't in the harness to verify there isn't a short inside the harness. Both low/high hooked up - same outcome - high speed kicks off after a second or two.

So then I unscrewed the circuit board from the panel and check the back for any burnt up spots or melted solder blobs. It all looked fine. All fuses tested fine for continuity.

Does this sound like a short inside the relay? The relay will click and switch just fine from off/low/high. The only issue is when both the low and high wires are connected at the same time to the board.

 

[Bama Rambler]

that does sound like a problem inside the relay. I would unhook all the wires from the relay and test for continuity between the high and the low contacts. There should not be any continuity between the high and low contacts.

 

[PoolSchoolMN]

I sent a private message to nmasino but I also wanted to see if anyone else has any info for me.

My situation is this. My hot tub was working just fine until 2 weeks ago when it made a really loud noise which ended up being a seized bearing on my pump. I ordered and installed a new pump and now I am having the same issue. My low speed works just fine. When high speed is engaged it will shut off within 1 second. It appears that low speed and high speed are both trying to work. If i disconnect low speed wire from the pump then the high speed works just fine. I'm thinking it's either a high speed relay or low speed relay. I have no idea which part of the circuit board this is and what it involves to fix.

Any help would be great.