Water tank sensor

[Jeremy Parrett]

I am getting a constant 50% reading from the water tank sensor. Lazy-days just serviced the whole system!  I have a 2000 Marquis Amethyst. I would like to know where the sensor is located, so I can check the connections.
I understand Beaver in Bend Oregon has some replacement sensors if I need them.

[Bruce Benson]

On the 2001 the sensor is on the front end of the tank near the drain valve.  The sensor is apt to fail due to the location and their sensitivity.  When the coach stops suddenly the water rushes forward and slams into the sensor.  The factories solution for this was to put a flow restricting washer between the tank and the sensor with about an 1/8 inch hole in it.  Beaver Coach Sales solution 4 years ago was to put a 90 on the line, thus taking the sensor somewhat out of harms way.  

The 90 is what I have in mine and it seems to work.  Our readings can be sporadic which I think is a poor connection somewhere.  The readings are either very good, which is usually the case. or very bad.  The bad readings always happen when we are dry camping of course.

The fact that yours shows a constant 50 probably rules out the possibility of recalibration.  If you want to try that let me know and I will send you the instructions

You will not enjoy the price of the new sensor.

[Jeremy Parrett]

Hi Bruce,
I expect the 2000 is the same as your 2001, so when I am able (back sprain ), I will take a look in the bay near the water dump valve.  
Just to clarify the position of the water tank and sensor.......  my dump valve is on the slide out bay forward bulkhead beside  the Hurricane furnace bay .  I guess the sensor must be there too.....yes?

Jeremy,  2000 Marquis Amethyst C12

[Bruce Benson]

Yes.  It is in the front end of the tank near that bulkhead.  The tank is mounted a few inches to the rear of the bulkhead so there is a crack there and that is where it is mounted.    

[Jeremy Parrett]

Hi Bruce,
Using the fresh water the other day dry camping, the monitor panel dropped to 30%.  I am wondering if recalibrating the sensor might solve the problem. I know Lazy-days serviced this system.  Possibly when they checked ( disconnected ) the sensor they  upset its calibration!   Jeremy

[Bruce Benson]

My 2001 has the CMP-20 Coach Monitoring System.  Assuming yours has the same system, the programing information that I have is as follows:

1) Place the unit in the Diagnostic Mode.  You do this by pushing all four touch keypad buttons on the CMP-20, inside of your coach, down at the same exact time.  This takes me both hands and a few tries to accomplish.  You will see the display change to raw full and empty data when you get into this mode.

2) Program the TL-II.  This is a module located, in my coach, above the water pump bay in the rear of the basement storage area.  There are several of the metal boxes throughout the bay and a few of them are located above the water pump bay.  They have green indicator lights on them.  There is a mini rotary selector switch in the top of the TL-II module with a push button next to it. In my coach, the module must be taken off the bulkhead to access these switches.  Calibration is accomplished by adjusting the fluid in the tank to the proper level, selecting the appropriate position on the rotary selector and pushing the button.

Position 0 = no action - switch must be left in this position for proper operation
Position 1 = set empty calibration on fresh tank
Position 2 = set empty calibration on gray tank
Position 3 = set empty calibration on black tank
Position 4 = unused
Position 5 = set full calibration on fresh tank
Position 6 = set full calibration on gray tank
Position 7 = set full calibration on black tank
Position 8 = unused
Position 9 = Restore factory defaults to all tanks

When you push the program button you should watch the green light and count the flashes:

Flashes
1 = Calibration good
2 = 0 selected on rotary switch - no acton
3 = Invalid tank (4 or 8 selected)
4 = Empty calibration error - tank not empty - sensor or channel bad
5 = Full calibration error - tank probably not full - sensor or channel bad
6 = Full calibration error - tank probably over full - sensor or channel bad

3) Be sure the rotary switch is returned to the 0 position.  Turn the CMP-20 off and then back on to exit the diagnostic mode.  Your new calibration will be retained in memory even if power is off.

Now that I have given you all of this, I need to say that I have never done this on my coach and the manual states that full calibration should not be necessary.  

I would assume that a sensor that falls too far outside of the expected parameters would come in as a calibration error.  

[Jeremy Parrett]

Bruce,
Many thanks for all this information. I will recalibrate the water tank, and let you know what happens.

Jeremy

[Gerald Farris]

We are getting a little off here in that Jeremy's coach is a 2000 Marquis and not a 2001, although the information that was posted above can be very beneficial to owners with coaches equipped with a CMP 20 panel. The 2000 Marquis was equipped with a CMP 10 panel that uses electrical probes through the side of the tank that become conductive when the liquid in the tank comes into contact with the positive and negative probe at each level on the tank that the panel is designed to read. There is no calibration for this system that I know of.

The panel will read wrong if one or more of the probes on the inside of the tank becomes contaminated in a manner that will cause reduced resistance (short circuit) between the positive and negative terminal. You will also receive incorrect readings if there are loose or corroded connections where the system wires hook-up to the probes at the tank.

Gerald  

[Bruce Benson]

I think that no two coaches left Beaver the same nor have been modified the same.  It is very important to me to qualify what I offer here so that the recipient can make a determination that it does or does not pertain to his particular coach.

I live in a very small world in that I know my coach pretty well but seldom see other coaches.  I hope that I make the distinction clear in my postings that I am speaking only about my particular coach.

[Jeremy Parrett]

Thank you again for clarifying this issue.  I have, as Gerald states, the CMP-10 system, and so will have to check the physical connections on the water tank probes.  

[Jeremy Parrett]

I have solved the water tank sensor problem . The issue was simply that behind the CMP-10 panel there are the connectors for all the switches on the board directly underneath. In changing the water pump monitor light I had pulled the water fill switch connector wire clean out of its spade connector. This became evident when circuit testing the relay that works the fill valve.  The tank now fills to capacity and the CMP-10 reads correctly .   This is the second spade connector on my coach that has caused a circuit failure because the crimp was not done correctly. Thanks to everyone's input.
 Jane and I are going to Baja Mexico Jan 27th with 14 other RV's escorted by   www.bajawinters.com

[Joel Ashley]

Long ago and far away an experienced auto parts clerk once told me to substitute soldered joints for crimped ones wherever possible, whenever I repaired 12v. connections.  Crimped joints were invented because they are faster, and in production lines that goes to the bottom line.   But in this case faster isn't better.

I bought a mini-torch many years ago, for portability and on-vehicle repairs, and to this day I replace crimps with solder wherever I can in repairs or installations.  Using alligator clips as heat sinks on wires keeps insulation from burning.  I got one of those Coleman soldering pens too, but discovered they are only practical for circuit boards or 22 guage wire, and small diameter solder, because their amperage is useless for the heat conduction necessary on larger wires;  so I can't advise buying one in lieu of a torch.  I carry a supply of various shrink-tubing sizes also, to seal solder-repaired wires afterward -the mini-torch does second duty there as well.  And the mini-torch heats joints far faster than my workbench soldering iron/gun.  It's just not always practical or safe, such as in tight configurations near flammables or around battery banks.

 ;)Joel

[Jeremy Parrett]

Hi Joel,
 I own a 40 ft Corbin 39 blue water sailboat. ALL the spade connectors are soldered and crimped by yours truly. This is mandatory in a salt water environment, and in a Beaver Marquis apparently !!
Thanks for the advice .  Jane and I are off to the Baja, Mexico Jan 27th till March 20th.  Busy buying new steering tires etc.