Today I added a fill and flush switch to my Thetford toilet. I know that a lot of you have done this already but I thought I would post this simple way to add the switch.
The Problem: When I go to the bathroom, I have to either put my hand behind the toilet and find the switch and press the button to flush before I stand up while the water splashes on me or stand up and turn around and practically put my face in the bowl to reach the buttons in the back of the toilet to flush.
Solution: Add a remote switch to be able to fill and flush without fishing around for the fill/flush button and without getting my bottom wet.
I pulled off the access panel in the pantry slide and to see where the wires could come out. I cut a hole on other side of the wall of the panel next to the paper roll in the bathroom and ran a 4 conductor 22 gauge wire along the inside of the wall (it is a sandwich wall about 1" thick) toward the back and to my surprise it came out at the side wall of the MH in the back of the cabinet and fell down on to the plumbing below.
Then I fished the wire through the bushing that holds fill hose and 12v wires and up to the back of the toilet. I took the collar stay off with a quarter turn and carefully pulled the fill/flush button assembly out so I could work on it.
Warning: You need to be really careful that you run the wire along side the wire that is already there and up through the collar so that when you put it all back together you are able to place the collar on the assembly without having the wire get in the way. Because the collar and wires are difficult to access in the back of the toilet, you need to be careful that the wire is not running on the opposite side of the support bar in the back. Bottom line is that both wires need to run in the same holes and behind the same bar behind the toilet.
I took off the rubber, water proof cover, and examined the circuit.
Sw1 is the flush button and Sw2 is the fill button. I wired the four conductor wire to position 1 and 4 on the flush and 1 and 4 on the fill as shown. I used lots of flux and a little solder. I purchased the switch from Amazon. The current draw is in the milliamps, so the 22 gauge wire is plenty.
https://www.amazon.com/gp/product/B0...0?ie=UTF8&th=1
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I wired the end of the switch to this momentary on/off/on switch and now I can fill and flush the toilet without bending over and leaning into the toilet to do so. The old button works the same and the new button works perfectly. It took about 4 hours.