I have been getting the 121 error and my pool is not generating chlorine. I read about the voltage issue and metered at 36v dc. This is a bit high, correct? I have removed the cell and gave it an acid bath from a few known good guides. The cell did not foam/phis up and appears to be clean. I also read it could be the flow sensor.

flow sensor shows the following.

3 leads
0 0
the bottom does not connect to any of the 8 pins
top left goes to the yellow pin
top right goes to the brown pin

If I check continuity from brown to yellow I get:
37 ohms pool off
37 ohms pool on ( reversing indicated )
37 ohms pool on ( reversing, flow indicated )
37 ohms pool on ( flow indicated ) : pending results.

guessing its stuck close? Yet the flow light comes and an off.

The sensor costs my arm, and the cell my leg. I can afford one or the other but not both. Is this switch in fact stuck? I see the manufacture has filled the active switch with a poly like substance so that the 10 sent switch can not be replaced.