Tank sensor wiring issue...

Quick update here...had it in for service and they checked this out. After filling and emptying tanks and checking sensor pack they took the control panel off inside the trailer and wire was pinched causing a ground issue. Dougrainer gets the gold star.

Best fix is just replace the system with a SeeLeval system.

Dusty

I had the same problem with a brand new Arctic Fox Pickup Camper. It was replaced under warranty with the following problem description.
"It was the Sensor Pac. R&R the gray tank Sensor Pac. Tested on Monitor, test OK.

This fixed the problem and the tank has read adequately for the past year.

Most common fix is the FEED wire from the resistor going to the inside panel is grounded someplace. Disconnect the Gray tank wire at the inside panel and if it reads empty that wire is shorted to ground. Doug

Just fill the tank about 1/4 full and go for a good dive. The sloshing of the water will clean the sensors better than anything else you can do. Dump the water immediately when returning home, and you'll be good to go for a while again.

But, you can never depend on those sensors to actually work right. It's better to just get more familiar with your camper, learn to estimate your water usage, and fill the fresh water tank often, and dump the black-grey tanks often until you get a good grip on your usage. Then, you'll never need those sensors again.

DrewE wrote:
The commonest cause of this is goop building up on the inside wall of the tank and connecting the probes together. Problems with the resistor pack are pretty rare.

I understand that too, but assuming from the factory and dealer that the tank has only ever had water in it from testing there should be no goop yet. Probably more of an annoyance since I know eventually tank sensors are pretty useless, but I’d like to have it working for now if possible.

Keep us posted on what you find. I have the same problem with my black tank. Reads full when empty. Winter sucks. It's -7deg. F today so with the TT winterized and stored it will be at least 3-4 months before it is warm enough for me to get to it.

The commonest cause of this is goop building up on the inside wall of the tank and connecting the probes together. Problems with the resistor pack are pretty rare.

The resistor pack is simply wired with resistors in series, connected between successive probe leads. Thus, there's one between "empty" (really the ground return) and "one-third", one between "one-third" and "two-thirds", and another between "two-thrids" and "full". I think, but don't know for sure, that the resistors are probably all the same nominal value, so the resistance between "full" and "empty" should probably be three times that between "empty" and "one-third".

The sensor system works by having the fluid in the tank more or less short out one or more of the resistors, which alters the overall resistance of the unit and is detected by the readout display unit. It's not very sophisticated or liable to electrical problems beyond things like broken wires etc.

2oldman wrote:
Few of us have sensors that work.

I understand that...but being brand new I’d like them to work at least until they get gunked up.

Few of us have sensors that work.