Is it the C2 bench type? seems like it so you found the motor.
Test: Turn on the 12volt light in or one near the toilet you can see press the fllush see if the light dims if not no power is getting to the pump so mybe fuse or bad/corroded connection or the micro switch.
If the light dims then the pump is either knackered or jammed try this first remove the pump from tank up end the pump and with a small instrument turn the impeler until it feels free, they sometime stick with lime build up on the shaft. Replace pump try again.
If you test for current at the pump end it should read 12 or there abouts to operate the pump.
Failing that www.thetford-europe.com or if in Australia www.thetford.com.au. [it's a world forum] you can get free pdf repair downloads although not on pumps or you can send them a question on page three ask thetford.
bob, March 2010
