Toilet flush..

Remove the pump & bench test it with a known 12 volt supply to prove the pump itself. 

Use a multimeter at the wiring in the toilet ie when you press the button do you get 12 volts? Is there 12 volts before the button/switch?

Hello and thank you for your response..I will borrow a tester from work and give it a go..many thanks

If the pump itself is OK, then I would suspect either a damp PCB or a poor connection  to the PCB.

Hi there thank you for your reply..I am going to give it a go either today or tomorrow and will let you know..many thanks.

I never understood why it was felt that the old manual pump wasn't satisfactory. Putting sensitive electronics in a damp environment was always going to be a bad idea. Are we all getting that lazy?

I managed to break the one in our first caravan. Pumped too hard.😂

https://www.youtube.com/watch?v=fXEWut4YGfY

Or Dan shows a different set up .... is it the same pump? 😊 

I'm not familiar with your caravan so don't know what make of toilet you have. Our 2015 Lunar has a Dometic toilet. If this is what is in yours, there is a 7.5 amp fuse under the flush push-button. The whole push-button assembly has to be carefully prised out using a suitable tool, (something like a narrow bladed knife point). It has two fairly strong spring clips underneath. I had to remove mine to fit a replacement anti-siphon valve,