Serial Number is J2D1014 I believe it was purchased 11/02, I've owned it for 3 1/2 years.
I opened the panel and on the left side looks like the lines your talking about. That's where all the "noise" is.
I know the electrician that installed the tub, will ask him about the size of the wire. He's always been top notch so I expect it will be of decent size.
Not sure how to check the impeller.
When the pump energizes, it just about reaches full power, but spends more time building up pressure. My times are off a bit, probably a second-.and a half to cycle.
I tried with caps on and off. They are always completely submerged.
One thing to add. This problem began when the water level was low, flush with the top of the 4 neck jets. The water has been this low before without a problem.
thanks,
jeff