Thetford 402C Cassette Toilet Problems

Discussion in 'Port-A-Potties / Cassette Toilets / Bath Houses' started by Cabello Rojo, Sep 6, 2019.

  1. Cabello Rojo

    Cabello Rojo New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Sep 6, 2019
    [CC]Hi! I'm new to this site and to PUP camping. We've tent camped for years but finally decided to get off the ground. We recently purchased a used 2007 Fleetwood E2 which has needed more repairs than I thought when we purchased it. Our biggest problem so far is the Thetford 402C LH cassette toilet is broken. It has never flushed so we've just used the shower to add water to the bowl until I could repair it. The mechanical closure mechanism broke and pieces fell into the tank this past weekend. I tried to recover them when I dumped but obviously missed something; no big deal. I purchased a new replacement mechanism, water pump and control board online. I have repaired the closure and it works fine. I replaced the control panel but do not have power to the pump. I have 12v to the board and have removed the pump and jumped it and it runs fine. I don't believe the board is bad.
    Are there any interlocks that have to be met to allow the pump to come on with the switch?
    Flush water level shows @75% full and the holding tank is empty, also the "E" fuse underneath is not blown (but I replaced it anyway).
    I'm kinda out of ideas.
    Hope I'm posting this in the correct location..thanks
     
  2. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

    Messages:
    9,105
    Likes Received:
    6,493
    Joined:
    May 31, 2018
    Location:
    Nj
    I have an older hand pump one, on mine the hose was disconected and filled with gunk from not being used. Also the tank had to be flushed, it had all sorts of stuff in there that cloged the hose.
    Yours has a circuit board? Wouldn't just an on off switch be good enough? I relly really can't think of why a board is needed.
     
  3. Cabello Rojo

    Cabello Rojo New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Sep 6, 2019
    It's a shower and toilet in one unit. The board controls the electric pump and "full tank" indicator and makes the unit waterproof. An enclosed, spring loaded rocker switch is a final option.
     
  4. Sjm9911

    Sjm9911 Well-Known Member Gold Supporting Member

    Messages:
    9,105
    Likes Received:
    6,493
    Joined:
    May 31, 2018
    Location:
    Nj
    Ah, mine just has a float that never worked and an indicator level, lol. I would have to guess , if the pump works while jumped, and the power is going to the board, it would have to be a bad board. The pump dosent run at all when conected to the board ,right? No way for anything to be clogged in the lines?
     
  5. SteveP

    SteveP Well-Known Member Platinum Supporting Member

    Messages:
    2,092
    Likes Received:
    807
    Joined:
    May 21, 2015
    Mine has a 5 amp fuse where the factory oem wiring connects to the cassette wiring. Its almost hidden, on the non-hinge side when the access door is open, between the camper wall and the cassette. Then there's the 3 amp fuse in the blade switch, on the left wall of the cassette tunnel. If either of those is bad there's no power to the pump.
     
  6. Cabello Rojo

    Cabello Rojo New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Sep 6, 2019
    OOOhhh...I looked for any other fuses but haven't found anything except the 3 amp mounted to, what I believe is, the high level indicator (magnet sensor) on the inside upper wall.
    I have 12.7v to the board and also on the board connectors from the plug. There's a blue and brown wire(s) running to the pump and I show 12.3v if I keep my meter red on board red and alternate my black meter to either the blue or brown to the pump.
    Is there some sort of interlock to keep from running the pump if, say, the waste tank was removed? I see nothing that would prevent this unless the thing I believe is the high tank level switch is it and it's bad? IDK
    I'm going to go check for another fuse somewhere.
     
    Sjm9911 likes this.
  7. Cabello Rojo

    Cabello Rojo New Member

    Messages:
    4
    Likes Received:
    1
    Joined:
    Sep 6, 2019
    I couldn't find any other fuses except the 3amp mounted high underneath. I removed this fuse and I loose all power to the plug/board.
    It sure acts like a bad board. I'm going to call Thetford again.
     
  8. SteveP

    SteveP Well-Known Member Platinum Supporting Member

    Messages:
    2,092
    Likes Received:
    807
    Joined:
    May 21, 2015
    That is the blade switch. I don't know its function but I don't think it has anything to do with cassette level. I have no indicator but I still have the switch. If the 3 amp fuse is pulled the pump will not run. If the pump locks up the fuse will blow. Your thought that it may prevent the pump from running when the cassette is pulled may be correct.
     
  9. BillyMc

    BillyMc Well-Known Member

    Messages:
    2,045
    Likes Received:
    1,382
    Joined:
    Mar 25, 2018
    Location:
    South Carolina
    Ours didn't work when we bought it. It still doesn't work, but I haven't messed with it yet. We too just use the shower for water. The shower wand is an easy work around. I'll get around to checking it one day, but for now finishing solar setup trumps toilet pump.
     
  10. HappyTraveler

    HappyTraveler Well-Known Member

    Messages:
    547
    Likes Received:
    464
    Joined:
    Apr 30, 2019
    Location:
    New York
    Seeing posts like this makes me glad our toilet is such a simple set-up. :)
     
  11. Sotovoce

    Sotovoce Active Member

    Messages:
    264
    Likes Received:
    145
    Joined:
    Jun 27, 2015
    Location:
    Georgia
    Ditto, HappyTraveler!
     
  12. Thorofin

    Thorofin New Member

    Messages:
    26
    Likes Received:
    7
    Joined:
    May 27, 2020
    Location:
    Tampa, FL
    Was there ever a solution to this issue?
     

Share This Page