no lights

[kelly1]

Hi folks. I'm restoring a '68, 30', sovereign land yacht and would appreciate your input on a small but frustrating problem. I've gone throught the entire electrical system and corrected whatever was necessary for safety and functionality. Everthing works and I even have correct polarity. The old girl has even been updated with an InteliPower 9100 and charge wizard. The only system I haven't been able to get to work correctly is the holding tank water level indicator? The main control panel shows one wire coming off the yellow light indicator and one wire coming off the red light indicator. These two wires (look almost like thin speaker type wire) come out of the left rear well of the as over the area of the probe in the holding tank. The probe itself has 3 wires coming out of it. Red, Yellow, and White. Coming out of the same grommet hole as the two speaker wires is another wire which is much thicker? 10-12 guage. I scraped the paint off the wire sheath and it appears to be a dark blue color? I figured this must be some type of ground wire as it sparked when I briefly touched it to the + side of the battery? The owner's manual shows one wire goes to the probe's red wire and one goes to the yellow wire and the white is grounded. It doesn't show any other wire to attach to the probe and it doesn't show a third wire coming out of the rear of the as with the other 2 wires? I have tried every possible combination of connections and some that I shouldn't tried. For some reason, I am able to get both panel lights to activate when I connect the blue wire to both of the speaker-type wires and then connect them to the probe wires and ground the white to the body? I can't, however, get either light to activate individually. I used a glass of water to test the probe so I could get the 1/2 and 4/4 quantities visually. I also pulled the probe out of the tank and cleaned it thoroughly and lightly sanded the 3 probes. I also ohmed the probe and have continuity on all 3 metal probes? Your thoughts would be appreciated. Thanks Kelly1

[Janet]

Hi and welcome to the forums.

Use the search tool and search for hold tank sensor or holding tank indicator. I don't have these sensors in my tiny trailer - but I'm sure others will be able to help.