Well I have the SeeLevel II Tank Level Monitoring System installed for 2 of my 3 tanks. I am pleased with the results I have obtained for the black and gray tanks. The elusive fresh water tank will have to wait a while before I can schedule the surgury for that operation. I intend to install a much larger dump outlet in that tank when I am in there.
I mounted the sender units on the ends of the black and gray tanks on the far side of the dump tube outlet -- only space I could find that was clear of the old probes. I prepared the tank surface by sanding and thoroughly cleaning with acetone before applying the sending units which are adhesive backed. Since there is only one shot at getting these right I made templates that the sending units would fit inside as placement guides. When I was satisfied with the placement of the guides I peeled off the backing and pressed the senders into place. I used Belden 8442 22 gauge unshielded pair in a vinyl jacket for the interconnections back to the display. No problems there.
The senders come in 16 inch strips which are cut to the proper length for the individual tanks. I found that 8" was correct for the black tank and 9" for the gray. The cuts are made in 1" increments. At these lengths I am getting 3% resolution on the display - that is the display changes 3% at a time. Much improved over the E, 1/3, 2/3, F system that didn't work anyway. This past week I had an opportunity to fill both tanks and the display indicated correctly at the 100% levels. Very happy with the results - looking forward to adding that fresh water tank sender soon.
The Display is mounted in my Custom Instrument Panel in the Closet. I cut the old tank level portion from the original controls and mounted the SeeLevel display in its place. This would be a viable thing to do without having a custom cabinet. You can see pictures of the results here:
Instrument Panel
The only issue I have is that the programming and testing procedure requires the meter to be powered off and turned on with certain switches activated. That is not easy for one person to do unless a switch is installed to cut the power. I will do that if it becomes a nuisance. Very easy to do.