Tanks Horst tank Probe Installation

[Herk7769]

Well, what a wonderful two days this has been. (One more to go but it is inside the camper work unrelated to the Horst Probes). (TV outlets in storage area and Inverter circuits to Entertainment cenrter - More on that later).

So, Have you ever wondered as I have, just what is under the Black Coreplast belly liner? What do the tanks look like? How is the handle hooked up to the dump valves? WHERE is the fresh water tank and how is the vent actually plumbed?

Well you nice folks will get a ring side seat for this project.
STEP ONE:
DO NOT PICK A WINDY DAY. Seriously what a bummer trying to fight that plastic sheet and not tear anything. Glad it was not so bad today putting it back up. Worse, since the project involved running coax and Romex to the rear entertainment center, not only the front cover, but the rear cover had to come off.

There is mud everywhere (STILL after 3 washes) from ONE night camping at Fort Bragg. (Never again).

I found out the camper was wired just like I would. Home Run and dangling.

More in Post #2

[Herk7769]

The trick to getting the old probes out is to remove the first locking nut, take the wire off, unscrew the second nut till it is at the TOP of the threaded rod and bang it flush with the tank. Then using side cutters grasp the rubber seal and twist that sucker right out.

The new probes are installed in the top two spots. NOTE THE FLATS. They must point down to allow the TP shield to be on top.

[Herk7769]

The old probes look like they are like grommets, but apparently they get that shape when they are tighened down. Here is a comparison photo of the Black tank probes and the New Horst black tank probes. The one with the spiral on the end is the gray water probe.

[Herk7769]

Folks will tell you there is no one around more (pardon the expression) anal about flushing and cleaning the black tank, and you can tell from the photo with the side cutters (though still shockingly covered with bits) fairly clean after two years of mostly dry camping.

NOT SO WITH THE GRAY TANK. Who ever said you don't need to worry about the gray tank because it gets all the soap, need to look at these probes. The photo with the 4 probes in it were gray water probes just as they came out. The single one is the bottom black water probe.

[Herk7769]

So why does my tank read the way it does? Why does the 1/3 full light come on with the first flush? Because the 1/3 light is really a "Not Empty" light.

Check out where they are installed. The lowest screw head on the righ hand side is the 1/3 full light. The one to the left of the dump valve is the "Ground" for all three lights. When the tank is empty, the "Empty" light just means the system has power to the red resistor pack in the photo. When the water level hits the lowest probe, the 1/3 light goes on. As it rises to the 2nd probe (about 1/2 actual) the 2/3 light goes on, at the 3rd light the panel will say "full".

[Herk7769]

Well, I found it.
The vent line looks good and straight and at the top (sorta) where it is supposed to be. I was shocked (not literally ) to find out the fresh tank DOES have a heating pad. It is the only tank supported by a piece of plywood and is located between the wheels.

Oh, I did not change the fresh water tank probes because they indicate fine. Note the indicator levels though and the location of the 12VDC pump inlet. It is "full" (water gushing out the vent) when it is not actually full and the pump will suck air when it is not actually "empty." The Petcock drain IS at a relatively low point and will drain the tank almost dry.

[Herk7769]

This thread will show a typical Horst probe installation.