All tank level lights are on

Dave1330 · 09-07-2009, 12:23 PM

Purchased this 05 journey 36g 6 months ago.

The black, gray, and fresh water tank level lights are all on when you push the respective buttons. The lp levels lights work correctly.

I have searched this forum and there is a lot of info on this system, but have not seen anything the same as my issue

I can see the sensors on the side of one of the tanks and I believe that they are the newer type. they are flat, black in color with a big + sign in the middle of them.

I have been living with this since I bought the coach. These systems have their issues, but I don't expect it to work perfectly. The thing that is funny is that the lp works , and I would guess if it was a dirty tank issue, the fresh tank levels would still work.

The wiring diagrams are helpful, but I still have not figured it out. When I pulled the panel out to look at the wiring, there was no obvious problems.

A previous post said there is a sensitivity adjustment, but I believe that is for the older system.

Thanks in advance, Dave

Dave1330 · 09-07-2009, 07:49 PM

Still not fixed, but here is the latest info.

When i unplugged the sensors at the tank, just one light comes on.

There is a sensitivity adjustment on the circuit board, it sweeps just under 1 turn, it didn't change anything when i adjusted it.

It seems impossible that all three tanks have bad sensors, but unplugging them did put the lights out.

ideas ?

Thanks, Dave

ernieh · 09-07-2009, 08:02 PM

Perhaps you could borrow a board to see if the problem disappears.

What are friends for?

DAN L · 09-08-2009, 12:50 AM

Quote:

Originally Posted by Dave1330

Purchased this 05 journey 36g 6 months ago.

The black, gray, and fresh water tank level lights are all on when you push the respective buttons. The lp levels lights work correctly.

I have searched this forum and there is a lot of info on this system, but have not seen anything the same as my issue

I can see the sensors on the side of one of the tanks and I believe that they are the newer type. they are flat, black in color with a big + sign in the middle of them.

I have been living with this since I bought the coach. These systems have their issues, but I don't expect it to work perfectly. The thing that is funny is that the lp works , and I would guess if it was a dirty tank issue, the fresh tank levels would still work.

The wiring diagrams are helpful, but I still have not figured it out. When I pulled the panel out to look at the wiring, there was no obvious problems.

A previous post said there is a sensitivity adjustment, but I believe that is for the older system.

Thanks in advance, Dave

mine was 5 years old when i got it and the indicators were the same.
chlorinate (20 oz for 80 gal) the fresh water tank and let it sit for 24 hrs. shut off the kitchen water filter before chlorinating. put at least a 5 gallon bucket of ice in the black tank. thetford makes a cleaning additive for the gray tank. i wish i could have put ice in the gray tank too. then drive the moho around with about 3/4 full tanks and with the chemicals installed.
i use a capful of calgon liquid water softener from wally world in the gray and black tanks at every dump to keep the indicators operating properly.
you should either treat your fresh water tank with vinegar or chlorine bleach twice a year. i used vinegar (3 gal for 80 gal) last time instead of bleach. either one will clean the sides of the tank and the sensors and keep the water from making you sick. vinegar is easier because you only have to fill, rinse, and flush the tank 2 times. it takes 4 times with bleach.
we use an everpure ql3 1/2 micron water filter at the kitchen sink for drinking water and ice.

Clay L · 09-08-2009, 08:58 AM

Quote:

Originally Posted by Dave1330

Still not fixed, but here is the latest info.

When i unplugged the sensors at the tank, just one light comes on.

There is a sensitivity adjustment on the circuit board, it sweeps just under 1 turn, it didn't change anything when i adjusted it.

It seems impossible that all three tanks have bad sensors, but unplugging them did put the lights out.

ideas ?

Thanks, Dave

The adjustment is only for the LP gauge.

It's very unusual for the fresh water tank sensors to show full when the tank is empty. It takes a lot of crud on the tank walls to cause that.
I would bet on a pc board problem.

The display panel has five "LM339 Low Power Low Offset Voltage Quad Comparator" ICs (one for each waste tank, one for the propane tank, the water tank and one for the battery voltage) that are used to sense the voltage drops across the sensors and activate the proper LED.

The sensors act like a switch and are either closed or open and in effect short out a resistor across the "switch" thus changing the voltage level that the ICs are sensing.

Without an actual schematic it's hard to figure out why the LP and battery sensing ICs are okay and the tank ICs are bad. I don't know what the common failure element might be unless all the tank walls are really that cruddy.

wa8yxm · 09-08-2009, 12:22 PM

That happened to me once... All the lights came on, even though the tanks were all empty and at least one tank I've never had a problem with

So,,, I checked, and found the GROUND WIRE on the panel... had come loose from crimp on connector they used to hook the very tiny wire from the panel to the like 12ga wire in the harness.

The re-do, involved solder, and a bit of heat shrink tubing, and has not been a problem since

(I am, after all, a certified electronics technician.... I put my training to use)

Moral.. Check panel ground

Dave1330 · 09-08-2009, 02:50 PM

Thanks for all the replies.

This motorhome is a 2005 and they changed the sensors and system in early 05. there are no contacts that go into the tank like the previous setup. Cleaning the tanks is a great idea, and i will do it, but these contacts are adhered to the outside of the tanks like a pad and they are wire in series with a plug on the end.

The battery voltage is seperate and digital.

The board doesn't show any burn marks or irreglarities, but i am thinking it could be the problem.

I looked for a ground wire issue and am still looking, as that sounds like the most probable, but the fact that the lp works throws me off. there are 4 buttons and lights, fresh,gray,black, and lp and i believe they use the same ground. the lp does use a tank mounted sender that i assume is just a ressitor/reastat

any and all ideas are appreciated

thanks, dave

ernieh · 09-08-2009, 07:28 PM

The LP sensing is the same as the older models. I converted my 03 to the newer system and it has been very reliable. I had to change the sensors on the tanks and circuit board. Nothing was required for the LP.

DAN L · 09-09-2009, 01:15 AM

Quote:

Originally Posted by Dave1330

Thanks for all the replies.

This motorhome is a 2005 and they changed the sensors and system in early 05. there are no contacts that go into the tank like the previous setup. Cleaning the tanks is a great idea, and i will do it, but these contacts are adhered to the outside of the tanks like a pad and they are wire in series with a plug on the end.

The battery voltage is seperate and digital.

The board doesn't show any burn marks or irreglarities, but i am thinking it could be the problem.

I looked for a ground wire issue and am still looking, as that sounds like the most probable, but the fact that the lp works throws me off. there are 4 buttons and lights, fresh,gray,black, and lp and i believe they use the same ground. the lp does use a tank mounted sender that i assume is just a ressitor/reastat

any and all ideas are appreciated

thanks, dave

the crud on the inside tank walls conducts electricity, thus disrupting the indicating system. it only takes a film to do this.

DavidC1225 · 09-09-2009, 03:18 PM

Get a multi-meter and set it to read AC voltage and connect it to a DC outlet. If the meter reads more than 1 AC volt, the converter is faulty and must be replaced. My tank levels were doing the same thing, and I tried most of the remedies mentioned here. I just happened to check the levels when not connected to shore power and when the genset was not running and the level readings were accurate. Called Winnebago technical support and the tech had me do the test. The converter was putting over 30 AC volts through the DC circuit, causing the level meters to read at the top of the scale. The LP meter was not affected for some reason. It was always accurate.

Dave1330 · 12-06-2009, 12:37 PM

well 3 months later, I have an update, took the circuit board out and tried it in a friends coach, it works, so it is not the board. I will be looking at the grounds and also check the lights without shore power or gen running. Any other ideas ?

Dave

ROMAD · 12-06-2009, 01:23 PM

My 07 coach was doing the same thing when I picked it up. Turned out to be a bad converter (Too much ripple on the 12 DC)! Try checking the tank levels with the coach disconnected from shore power and no generator running. That way the board is running on just the batteries. If it reads correctly your converter is bad... good luck.