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92 U240 grey & black tank sensors

May 27, 2011, 04:39:45 pm

Does anyone know where the tanks sensors are on the grey and black tanks on my rig and what type they'd probably be and how to access them?  I suspected they were on the tank ends behind the flimsy panel in the water/sewer/electrical compartment but they are not.  The only other part of the tank I can eyeball is the other ends of the tank behind the batteries.  These are the compartments just forward of the rear wheels on either side.  Must not be the taped on sensors but internal? I asked Brett Wolfe but he said he's never had to mess with them and doesn't know.  I'm tempted to ask for a private message response as this is my only chance to know something about this generation of U225 or U240 that Brett doesn't already know.  The fresh water sensor always works fine and the grey was always close to but the black has been problematic.  I thought the problem was gunk on the tank walls at the sensor because I've been adding Calgon liquid water softener a few days before moving the rig and then throwing some ice down the toilet before pulling out and when I get where I'm going the black tank reads accurate again.  Good trick I picked up on the old forum.  Had trouble finding the Calgon.  Some Walmarts sell it and recently I noticed it on the shelf at Publix supermarket.  I guess this trick works good on probe sensors too if that is what I have.

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Re: 92 U240 grey & black tank sensors

Reply #1 – May 27, 2011, 05:03:10 pm

Inaccurate (high) black tank readings are just a part of the original system. You would have to go to an external sender to get reliable readings.  As I mentioned to you by e-mail, this is not of enough interest to me to delve into it.  Sure, like you I can clean the senders, and they will read accurately for a time or two, but then back to inaccurate readings. Accurate black tank readings has passed into "I already know how to manage this issue"-- the gauge readings being more a curiosity than a necessity.

As you have found, you CAN clean the sensors-- though I am not sure it is worth the effort.  The good news is that  most of us can predict when we need to dump the black tank anyway AND if you are dry camping, you will be totally out of potable water before you need to consider dumping.

Brett

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Re: 92 U240 grey & black tank sensors

Reply #2 – May 27, 2011, 05:45:52 pm

Dwayne, I am surprised that you cannot see the senders behind the wall in the dump compartment. As I recall, my 93 U225 had button senders on that end of the tanks that were readily visible. My Audit screen went out so I changed to the SeeLevel II, external tank monitoring system and used the original wiring that was right behind the wall.

With my U300 I am kinda like Brett, I really don't care that much about accuracy and have stayed with original Audit system. My black tank also shows full long before it really is but I now know from experience that when I use up the water in my fresh water tank, its pretty close to time to dump my black and gray tanks. It just seems to work out with the U300. If you are really adventurous, you can shine a flashlight down the hole an literally see how full the tank is. 

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Re: 92 U240 grey & black tank sensors

Reply #3 – May 28, 2011, 10:45:04 am

Dewayne
My senors (95 U240) are in bay in front of rear duals passenger side. Next time before dumping, watch monitor while driving to dump station.

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Re: 92 U240 grey & black tank sensors

Reply #4 – May 28, 2011, 11:29:34 am

I can't see any wiring or sensors but have managed to live with the situation.  We typically are in a campground so fresh water is not via tankage.  I have discovered that when standing grey water appears in the tub/shower, it is time to dump the tanks.  Not the best method.  Grey always fills up before black.  Rick, I notice from your photo the good looking paint job...very nice.  I also noticed the entry steps.  My rig didn't have them and it sits so low (at correct height as per specs) that I figured they weren't used on this model.  I should've asked Brett about it.  He never mentioned that I was missing them when here last year.  They aren't really necessary but I'd like to know if they were OE or added-on and if original, are they automatic?  Perhaps by 95 they were used but not in 92.

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Re: 92 U240 grey & black tank sensors

Reply #5 – May 28, 2011, 03:33:56 pm

Dewayne
 Yes they are original and automatic.

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