Ought to do an update... seems the actuator is working OK, though I may look into getting it overhauled once the pool season is over. If I pick up on the seat, or otherwise put a "pull" load on the actuator, the rod starts to pull out along with some of the other "guts" of the unit. However the Linak website says that most of the actuators are designed to work only with "push" loads, which is all that the lift would see in normal use. As long as I stick to pushing, it seems to work fine.
I tested the motors by taking the 24VDC power supply box that I built to power my Hyperion charger out to the lift and doing jumper wires onto the plugs that went to the actuator and the boom rotation motor. Took a bit of fiddling, but both worked fine after a while. The actuator has two speeds depending on how you connect the three contacts on it's plug. The boom motor just has one, and reversing the leads on either plug reversed it's direction, as expected. It did seem like the seat travel was really not useful, as it went way up in the air, but only a few inches into the pool. However I observed that there were several different pivot point holes in the boom, and did some rough looking at the geometry and realized that I could re-arrange the pivots and make the chair end up with different ranges of travel. After doing so, I ended up with the seat travel range from a few inches above my wheelchair seat, to a couple of feet deep in the pool.
The control box didn't work when I connected the battery to it, but it did make a bunch of funky buzzing noises - I opened it up and found that it was wet inside. I took it apart, and cleaned the board as best I could, though there wasn't a lot of corrosion as it had a pretty thick layer of "conformal coating" on it. After cleaning it and letting it air dry for a while, I put it back together, and all the relays in it seemed to work when I pushed the buttons on the remote control. I put it back together and attempted to use it on the lift.
Despite working fine the day before, I found that the boom motor would only swing in one direction.

Opened the box back up, and tapped on the relays with a screwdriver handle, and it started working again... I transferred onto the seat and cycled the actuator up and down multiple times, it handled my weight with no problems. With the GF standing by to watch me, I finally swung out over the pool and went in. Did a bit of swimming, and different floats - no real problem other than it being a lot more work (more or less as I expected)
However my experimentation was interrupted when the lift started making noises and small movements with nobody touching the controls... :? I decided that I should get out while the getting was good, and got back on the seat and lifted up most of the way, but couldn't get the seat to go up all the way like it should have. However since I was above the pool deck, I swung back over, and with some difficulty, and help from the GF, was able to get back in my chair. Eventually found that the remote had also lost its waterproof seal, and taking it into the pool with me had caused it to get water inside, resulting in erratic operation...
As I wasn't sure of my ability to get the remote sealed back up properly, and knowing that conformal coating would make it difficult to replace the sticky relays in the control box, I decided to obtain replacements for the control box and remote... I found a place that could get me the parts for a sort of reasonable price, and have them ordered - hope to get them soon so that I can actually use the pool...
Gooserider