Carver Owners Forum

I replaced an old black water tank sensor and still have the same problem. Low light is on always regardless of level. I never shows any other light.
Any suggestions on electrical diagnosis steps.

You should be able to short the different pair wires to illuminate the other lights on it to rule out bad wiring or indicator lights.

My 2001 Carver 396 had the same problem.
The factory installed TankWatch® 4 Water/Holding Tank Monitor system completely failed last year. The tank sensor has 3 non serviceable reed switches inside the dip tubes that are used to complete the circuit to 3 different level lights on the monitor. After removing and testing the sensors from the tank, 2 of the 3 switches were bad.
I removed the monitor from the cabinet in the head and bench tested it and found non functional as well.
I replaced both units and now the system works perfectly giving me peace of mind.
The job took about 4 hours and over$400 in parts.

May want to take a peek at this link where I ended up scrapping the original Carver unit and going with a Blue Sea unit in the end. Has been flawless. viewtopic.php?f=7&t=6393&p=61028&hilit=oled+blue#p61028

Yes I tested the unit and compared readouts from Volt-Ohm meter. Sure enough the display was bad. Found a new replacement on eBay. Shipping from England. Thanks for all the responses.