Thetford C2 flush pump woes.

Discussion in 'Port-A-Potties / Cassette Toilets / Bath Houses' started by BillyMc, Apr 3, 2020.

  1. BillyMc

    BillyMc Well-Known Member

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    Boredom from being grounded by Corona lead me to start this repair. The fresh tank was nearly full of blue chemical. I don't know if that had anything to do with the pump being locked up or not. I tried to free it up to no avail. Finally bit the bullet and bought a new pump. After much searching I ended up spending over $40 for a pump then I get a suggestion from Ebay for an aftermarket one for less than half the cost of a Thetford pump. Probably would have bought the Thetford one anyway as the other one was shipping from somewhere in China. Got the new pump, but no power to it. Have power to the toilet, but not to the pump. A little research reveals that there is a 3amp fuse in the toilet. After cutting an access panel in the interior panel I can see and remove the fuse. After finding a magnifying glass I was able to determine that it is a 5mmX20MM 3amp GMA (fast blow) fuse. I have a six pack of these ordered and will use some trim molding to fashion a easily removable panel for accessing this fuse. Whoever designed where that fuse is need swift kicks in the @$$ while removing the fuse from a toilet mounted in a PUP using only their teeth.

    I was just using the shower wand to rinse the bowl prior to this and in hindsight maybe I should have just kept doing that. At least going forward we will not be using water from the main storage tank to rinse the toilet while boon docking.
     
  2. GreyFox

    GreyFox Well-Known Member

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    The Thetford C2 is an older version of electric flush cassette toilet and hasn't been sold for years - I'd say the motor lock up had more to do with aging than anything else. $40 to me is a small price to pay for the convenience of being able to use your CP. :)
     
  3. BillyMc

    BillyMc Well-Known Member

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    Where the fuse is located indicates it's the pre-June 94 version of the C2. I found $40 a fair price to pay, it's what you have to do to change the fuse that I find ridiculous. The pump is crazy easy to change. The pump not working wasn't stopping us from using it though, we just used the shower wand for rinsing it. I wanted it fixed, but didn't want to take time off camping and other things to fix it. Now that Corona has stopped everything we do except work, I'm getting things fixed. Probably should have drained that blue stuff out or worn gloves before I started though. A couple hours after feeling around for the screw to remove the pump, even though I washed my hands, under my wedding band turn red and started burning. Had to remove my band for a few days.
     
  4. BillyMc

    BillyMc Well-Known Member

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    Okay new fuse and check it before connecting new pump. When pressing switch volt reads 12.something then the flasher starts clicking and volt go up and down. I connect the pump and press the switch. The pump runs for about two seconds and the new fuse blows. Anyone ran across this problem?
     
  5. GreyFox

    GreyFox Well-Known Member

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    Flasher? [?:~{]
     
  6. BillyMc

    BillyMc Well-Known Member

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    Okay put in another new fuse and did some trouble shooting.
    1) Check current draw of the pump and it is about 0.7amp.
    2) Check current draw of toilet without pump connected. It jumps up and down, but never exceeds 0.5amp.
    3) This is well under the 3amp rating of the fuse. I hooked everything up with amp meter inline and tried it again. It pulses, and never reaches 2 amps.
    For now I'm calling it a bad fuse and going to let it go. This is my first electric flush toilet and I was expecting a steady stream of water when I mashed the button. With it having a flasher in it I'm guessing it is designed to pulse the water like that.
    Now to look through my molding scraps and fashion a removable panel to cover the access hole I cut.
     

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