Question

my electric flush on the thetford cassette c402 has not worked for some time, i have replaced the fuse, reed switch, wiring harness, pump and complete switch could you please advise if there is anything i have missed

Answer

Hi

It sounds like you have replaced all the parts connected to the flush, the only option left is one of the parts you replaced was faulty of there is a problem with the 12v supply to the toilet. I would suggest running a new 12v feed directly from a battery to the power inlet of the toilet to rule out a damaged wire in the supply, alternatively put a volt meter on the supply terminals and take a reading (I am presuming you have already done this and found a 12v supply), then get someone to press the flush button and see if this voltage disappears, if it does then there is a damaged wire in the supply feed