Ok, definitely don’t do anything that you’re not comfortable doing. Safety first.
There are several reasons that knowing the volts and amps will help.
1) To see if the voltage is good. If not, that could be a contributing factor.
2) To know the power draw. At full flow, the pump should be close to drawing the full load amps. If the flow is lower than it should be, the power will drop to lower than normal.
I went out today and veeeeeeery carefully measured the voltage at the motor. It's tight and the insulation on the wires is compromised... no room for error in there with the probes.
I got 240V on the dot, which is exactly what it was at the leads coming off the timer, so voltage is good and there's no loss in the wire. It's a short run, only about 6 feet.
The pump is pulling about 10.4 amps, though, which is almost a full amp higher than the max rated amperage of 9.6 (at 230V) printed on the motor.
Knowing the motor temperature can help determine if the motor is overheating. If it is, then it will use excess power making heat and that has to be accounted for when assessing power draw.
I let the pump run for about an hour and measured surface temp around the whole housing. The sides of the motor, about dead center lengthwise, were the hottest areas... a couple spots were 210F. At the top of the motor it varied from about 180-200 depending on where I was measuring. I'm sure some heat is dissipating from the top as well.
I'm not sure what a normal temp would be, but if this is hotter than it should be it could account for the increased power draw.
Knowing vacuum pressure can help determine if the suction line is partially clogged. If it is, then that’s going to still be a problem if the pump is replaced.
I realize that and understand it, I'm not just equipped at this time to measure it.
If you’re going to replace the pump anyway, you can take off the existing pump and use it to clear the suction lines.
With the pump off, you can sit it next to the pool and run a 2” line into the pool to see if the pump runs properly.
I might be a bit thick here, but I'm not sure how I would go about cleaning the suction lines with the pump. I would have to construct some sort of set of adapters and/or fittings to get this pump to be able to pull suction OUT of the vacuum port and/or skimmer port (reverse of normal flow), right? So...
... where does the water come from? If I put suction on the vacuum line, for example, the other end of that would be back at the pad... would I then have to connect a pipe to the other end and loop it around and back into the pool? Otherwise I'd have no water to suck.
I did try introducing some pressure and turbulence into the vacuum line (didn't have a way to do it to the skimmer yet...) by setting the valve to full vacuum side, disconnecting the hose from the vacuum and then quickly alternating between sucking it to the tile and then quickly pulling it off to cause pressure to spike and then a surge of water turbulence... my hope being if there was anything like leaves in a 90 or something that maybe it would dislodge and flush it through. I had pretty strong suction and nothing came out into the pump basket so either there's nothing clogged in that line or my experiment didn't do anything productive. I will have to figure out how to try to do the same thing on the skimmer.
If you can measure the rotational speed in RPM, that would be helpful.
There are a few ways to determine the RPM of a motor. One way is to use an optical tachometer.
LOL... yeah, no. That's not a common tool to just have laying around the house. Also, how the H would I even do that? How could you measure the RPM of the motor without some part of it being visible somehow?
I appreciate your suggestions but some of them are just not feasible for anyone who isn't a pro... most people are not going to have specialty tools and/or skills to rig things up in ways that you can probably do in your sleep.
It's kind of like me nonchalantly telling someone whose automotive knowledge extends to changing their own oil, air filter, or wiper blades, and saying "sure, just remove the valve covers and the top end of the engine and take the fuel injectors out... it's not too hard." But they'd need a lot of tools they've never heard of and about 20 years of experience working on engines to be comfortable doing that kind of surgery.
- - - Updated - - -
Not much of an idea what the capacitor (if that's what it is) is for. Appears to be wired to the GFCI? Might be a suppressor for noise on the neutral line if I had to guess.
Any chance it could be there to aid startup of the pool light for some reason? When I flick the light on I can see the amp draw spike over 5 for a brief instant and then it settles to about 3.3-3.4, so that's what, a 400W light?