I have just replaced the sensors on my black tank with the Horst Miracle Sensors. Prior to the change the tank always showed full regardless of whether we had just dumped. Since the change the tank always shows empty. Ground is good and wires are back in the original position (on the new sensors). What went wrong?
i would recheck and make sure a couple wires weren't switched. maybe the top and common. if that is good, see if they are tight.
that is abt all i can suggest. i don't see how anything else could have happened.
Take all the wires loose, make sure they are not touching anything, and then take a reading. Should be empty. If not, the problem is in the board, not the sensors.
If all tanks and you only worked on the black, the board is cooked.
If the black tank only.
PROBLEM:
DISPLAYS “F” ON ONE OR MORE TANKS, OTHERS TEST GOOD.
TEST:
(A) VERIFY THAT LEVELS IN TANKS DO NOT MATCH DISPLAY
(B) SWAP TANK CONNECTINS ON PANEL AS FOR PREVIOUS
PROBLEM. RESET TANKS TO SEE IF PROBLEM HAS ALSO
CHANGED TO ANOTHER TANK OR IS STILL IN THE SAME
TANK.
DIAGNOSIS:
(A) IF STEP (2) ABOVE STILL DISPLAYS “F” ON THE SAME
TANK, REPLACE PRINTED CIRCUIT BOARD.
(B) IF STEP (2) ABOVE DISPLAYS “F” ON DIFFERENT TANK,
THEM THE PROBLEM MAYBE A SHORT IN THE WIRING, A SIGNAL WIRE SHORTED TO GROUND WILL DISPLAY “F”
ON THE PANEL. REPAIR OR REPLACE WIRING.
My money is on you swapped the ground for a signal wire.
there is another item. where three of the wires attach to a small (postage stamp sized) box before the wire goes to the panel. when one of mine was showing full, someone at the factory pointed to that item. don't see how u could have damaged that unless it was pulled on.
if any part of it is still working. the only problem is the one tank, i would verify everything else to be right before replacing a board. if that board is in the display panel, i would think it would be dead on all tanks. i'm a little hard headed abt looking at something other that what i did to stop something from working.
the board may be ur problem but i would try and prove that before buying another. if all u did was swap probes but it was otherwise functioning, i would tend to look elsewhere first. when i couldn't find anything, i would take a bowl of water and place the common lead and then each of the other wires (individually) in it to see it anything changes.
make sure u didn't break one of the wires in the process of tightening them down.
I'd like to try this mod but my trailer has an enclosed underbelly. I'm kind of reluctant to try taking it down. Has anyone done this? If so, I'd like to hear of your experience with it.
We have been using PurePower enzyme additive in the black tank. This year I've been trying the GEO method and driving with just a few gallons of water, softener, and detergent in there trying to clean things up. But no luck so far. Black tank still shows full no matter what.
I suppose I could save myself the trouble and expense just by looking down the toilet bowl!!
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i have the probes and have been wanting to make the modification. i also have the underbelly enclosed. went in from the top and found that i would have to drill holes (the old probes are bonded in). even with a close quarter drill, i didn't have enough room to get between the sewer out line and the tank.
couldn't see how the sewer out line was attach so it's on hold. i noticed from the pictures on herk's that it appears there is a hose clamp holding it. i may tackle it after all.
underbelly has a section that is removable below the tanks. i'll lower that next. it will be on my bucket list.
i've had success getting my black sensor to show zero after massive flushing. it is short lived though, first flush and all the way up.
where three of the wires attach to a small (postage stamp sized) box before the wire goes to the panel.
Jim, that "box" is a resistor pack.
See the attached diagram. As the indicators are submerged the resistor pack finds grounds and changes the resistance of the circuit. That is why a shorted signal wire will always show "FULL"
Are you sure that they are "bonded" in? There is a rubber compression washer on my old probes. A pair of side cutters were all that was required to wiggle them out. Be sure to push the old threaded part into the tank a little ways to provide room for the compressed rubber to collapse and allow withdrawal of the probe.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Anyone having probelms with their indicators need to look at the Horst probe video AND read the troubleshooting guide I attached to my first post in this thread. It is all the way at the bottom.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
didn't know what it was. makes sense to limit current an more probes are flooded. do u happen to know if they are the same value for grey or black? looks like the black would much more conductive.
I was going to put in Horst sensors in my '13 Grey Wolf today, when I found out my sensors are bonded instead of screwed in. Did anyone ever discover an easy way get those things out? Whatever they used is tough stuff. I could drill new holes but that will involve dropping the tanks. That turns a 30 min job into a several hour job.
I was going to put in Horst sensors in my '13 Grey Wolf today, when I found out my sensors are bonded instead of screwed in. Did anyone ever discover an easy way get those things out? Whatever they used is tough stuff. I could drill new holes but that will involve dropping the tanks. That turns a 30 min job into a several hour job.
Are you sure they are bonded in? Can you post some photos?
The OEM probes should be squashed in place and can be pulled through once the nuts are removed...
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Hi Herk--
Hope the pic comes through. The metal you see is not a nut but a torix head screw that attaches the wire. It appears to have a large washer, like a fender washer, that is embedded in what was once a soft sealing material. It's hard as a rock now. I'm afraid I will be dropping the tanks and drilling new holes.
I have never seen that style of probe before. You would have to remove it to find out how big a hole in the tank there is under that washer.
It is a risk; no doubt.
If I were in your shoes I would do a lot more research and find out who made that probe and what an "uninstalled" one looked like.
Then you can make an informed decision on whether installing the Horst set is even feasible or not. Dropping the tank and drilling new holes next to the existing probes may very well be your only option if you do need to install new ones.
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Hi Herk--
Hope the pic comes through. The metal you see is not a nut but a torix head screw that attaches the wire. It appears to have a large washer, like a fender washer, that is embedded in what was once a soft sealing material. It's hard as a rock now. I'm afraid I will be dropping the tanks and drilling new holes.
Thanks Lou--
You bring up a very good point and that is I don't even know if the holes for the existing sensors are 3/8 holes. That, and the fact that I'll never be able to get the top ones out, makes dropping the tanks and drilling new holes the better way to go. That will wait for spring.
If this is the type you have, it looks like you just unscrew it and it will pop right out. The unit SHOULD be able to be reinstalled after cleaning if the hole in the tank is the wrong size (larger).
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Lou & Freya the wonder dog
2008 GMC Sierra 3000HD Allison Duramax
2019 Flagstaff 8529FL
Linear Mode
