Trooubleshooting an electric toilet

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DavidM

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Last night the Jabsco electric toilet stopped working and yes it was used first :eek:. So with a few after dinner drinks in me I started troubleshooting it. The toilet worked a few hours earlier but when I pushed the button before bedtime it made a low power sound and then just stopped. Further pushing did nothing.

So based on this, I got in my mind that this was an electric supply problem, not a motor failure. So I started tracing wire. The breaker was hot. Then I shorted the push button terminals and that did no good. I followed the wire from the toilet underneath the sink and then it disappeared behind the fridge.

Attempting to just get it flushing, even if cobbled together, I used the vent fan switch that was nearby and jumpered that output to the toilet motor terminal. Nothing. That should have given me a big clue, but it didn't register- too many after dinner drinks no doubt.

So, I decided to wait until morning to pull out the fridge as I was expecting a splice was bad behind it.

One of my problems is that I didn't have a good ground nearby to clip the negative lead on my meter to so I could check for hot points in the wiring. So the next morning I used the load side of the head vent switch. This is not a good ground as it goes through the fan, but I figured if I was just checking for voltage present, it would work- the fan windings wouldn't effect a voltage measurement if no current was flowing.

So the next morning with a clear head, I clipped on to that point and then checked the push button for power and yes I did have power at that point. But since that wire goes forward behind the fridge before it goes back to the toilet I still suspected something wrong in that wiring.

But then I had an epiphany. I cut back the insulation on the crimp connector that tied the leads from the toilet motor to the DC supply that ran behind the fridge. This was easily accessible underneath the sink in the head. Using the quasi ground from the head vent I checked for voltage at that point when I pushed the button. Violla, I had voltage.

That almost certainly meant that the motor was shot. Sure it could be a negative wire side problem, but the odds were small. The epiphany shifted my mind from a voltage supply problem to a motor problem and I am now 99.9% sure that is what it is.

So I have ordered a new motor and a pump rebuilding kit which I will install next week.

The moral of the story is don't get stuck on a single cause. Use a logical approach to trouble shooting. And don't do it after a few drinks at night!!

Clearing the toilet of its contents, fortunately no solids, was easy. I used the dinghy's manual bilge pump to dump it into a bucket, then dumped a half gallon of fresh water in and pumped that out. Shouldn't make much of a mess when I pull the pump out next week.

David
 
Before you order a new motor, look at the back of the motor. If my memory is working you should see a stub of shaft with a slot in it. Try turning it with a screw driver. If it's jammed you might free it up.

If you decide it's a bad motor, consider buying a whole new motor / pump assembly. It might be cheaper than a motor and repair kit. It will be a lot easier to install.

I've made the assumption that you have one of the basic 37010 series toilets.

This is my old company: Jabsco 37041-0010 Toilet Motor / Pump Assembly 12 v.
That is the one for raw water flush.
 
I am familiar with that slot on Jabsco macerator pumps. This pump doesn't have a slot. But even if it did, with no current flowing, I doubt that it is stuck. The macerator pump would pull high locked rotor current until you twisted it with that slot to get it started.

I have already ordered the motor kit from Amazon for about $140. Yes, it is a 37010 toilet.

Thanks for your thoughts.

David
 
I had the exact same issue last year, toilet was working, than not working, than to my surprise working for 2 to 3 flush and finally not working at all. In my case it was the motor the cause but more precisely the shaft contact located at the far end of the motor. Considering that this assembly was old enough I changed the whole thing for a new one. Don't want to mess with my toilets :D

Positive point: I know now how to disassemble my toilets and what are the parts involved :)

L.
 
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