Originally Posted by doodlebug52
WELL....after posting all the above...we emptied the tanks today. And guess what the gauges say! Black water says it's 3/4 full and gray water still empty. We have a faulty gauge. Guess I have to order a new one? I do note that instructions say they are unreliable anyway. So how do you know when your tanks are full??
You know the gray tank is full when water backs up in the shower
You know the black tank is full when the toilet won't flush
Seriously: The gauges are not broken, that is normal In a prior post I showed how they are often wired... Just a single wire from the panel to a plastic chip and wires from the chip to the sensors. The chip has 2 or 3 resistors in it. one per sensor (including the common sensor)
The Sensors are nothign fancy, just a nail or screw that extends into the tank.. That is all, they are NOT electronic at all
So how do you tell when it's Full... Two ways The one above or install a better gauge system such as the See-levelhttp://www.rvgauge.com/rv.htm
Here is the problem: IF there is any "Slime" or anythign else that sticks to the side of the tank or gets snagged on the sensor it still shows "Wet"
Normally the 1-down from Full sensor, will do this
I have used the "Geo" method (Empty tank add 1/2 cup each Dawn Dishwashign Liquid (regualr not anti-bacterial) 1/2 cup Calgon water softener (power/liquid, no difference) five gallons water, drive 50 miles, dump again) after doing this the tank showed FULL (Which it was, of soap bubbles) but it quickly dropped to EMPTY as the bubbles popped.
Or I can pressure wash the sensor wall (1/2 inch pipe, capped with 1/4 inch hole in the side of the cap (Drill in line with printing on the pipe) hose fitting on the top end, feed with anti-siphon valves (plural) and aim toward the sensor wall, move around some so you blast the whole wall, turn off water (NOTE you do with with the dump valve open) remove pipe and wipe with Clorox to clean, Wear disposable gloves, dispose of usign haz-mat protocall)