Just keeping you guys updated. Received the DC controller from China. I think I'm going to start a new thread at some point to make the info easier to find, but here is the preliminary results:
It actually arrived fairly quickly considering customs and all that. It's not fully installed yet because I've been wrestling with a leak issue, but initial testing on the bench shows a few things:
The pot doesnt fit and mount like OEM into the pod, its much smaller, but will fit with a washer to assist. The stalk is much smaller and not a half moon, so it mounts off center and spins in an elliptical path and not stay centered. Doesn't bother me that much at the moment, just mounting it so that its centered on full blast but will probably want to replace it eventually to have it centered. I could try machining it down but the stalk is so thin to begin with I don't think that approach will work. It is a 22k ohm and appears similar or exact to this: https://www.amazon.com/uxcell%C2%AE-.../dp/B00A0FUU9G
Probably shouldn't be that hard to replace with something that matches a little better. I don't know much about electronics to know what tolerances I have with the ohm range etc. I can tell you that at least 1/3 of the range at the bottom isn't usable as it doesn't supply enough voltage to power the blower. So even though its an infinite adjustment range, it occurs over less of the knob travel so really only a modest improvement of adjustability over the stock 3 positions.
Im not an engineer but my testing with my bench battery charger so far shows that it doesn't deliver the full input voltage to the output even on max setting when under load. It seems to be dropping about 1.5 - 2 volts under load which results in significantly less airflow from the blower on full. Have to see if this results in an actual airflow difference when installed. If so, my plan is to install a bypass switch under the dash just in case to bypass the full current directly to the blower as did the OEM switch. Not optimal and may have to continue looking for better DC controller, but such is the life of the test pilot.
Wont be much of an update for a while as I have a leak in my condenser outlet and need to pull the whole shebang out and get it repaired. In vying for the boneheaded move of the week, I forgot to hold the second nut when removing the condenser ac line and it twisted and ruptured. Hopefully it can be repaired and not replaced.