mikea,
I would be happy to help, but to be honest, I am a dumb-dum when it comes to trouble-shooting tank valves. I just learned there is supposed to be a bank of strange looking fuse thingies under my fridge that supports them. I have yet to take a peek. Contrary to popular belief, the relationship I have with our PC is on a "Need To Know" basis. I don't get into things until something goes wrong, something irritates me enough to make changes, or I have a itching creative idea. None of that has yet applied with tank valves, though one is on the back burner, considering duplicating tank valve control switches inside the bathroom so I can blend tanks from in there.
Regarding your tank sensors, I will share my experience with them. Our 2007 sensors work fine, just like they did when our PC was new. I wonder if it is because at the end of our RV season, I fill each waste tank with water and a 1/3 gallon of household bleach, soak for an hour, then drain, fill with fresh water, soak for another hour, then drain again. I do this to eliminate any sewer gas or other foul odors because we sleep above our PC as shown here.
