Sussex duo 2013

Hi my toilet flush pump was jammed. I removed it and freed it up and tested it on a 12volt jump starter.
Before I put it back into its pocket I checked to see what voltage I was getting at the push button PCB.
I found that there was no 12volt supply, The 12 volt supply is linked to the main water pump which works. So obviously the 10 amp fuse is okay.
There is another fuse by the toilet cassette, i found this was the wrong one it had a 10amp fuse which was intact but I replaced it with the suggested 3amp fuse.
I have no 12volt supply to this fuse, this is now where i,m stuck. I dont know where to go from this point, Is there another point where I can go to check for 12volt supply.
Obviously there will be a 12 volt supply at the main fuse board because the main water pump is working. I cannot beleive that there could be a break in the wire some where.
Before I put my camper to bed after last season all was working okay. I can understand the pump can get stuck after the black rubbish in the cistern flush tank.
Apparenently people are saying the pink flush solution causes that.

Does anyone have any help on the electrical problem

HI Ive now cut into the toilet feed and managed to get 14 volts before the PCB, I,m now assuming that the PCB must be faulty. Its possible that when the pump jammed it blew the PCB, probably because previous owner must have upgraded the fuse rating.
I know i,m answering my own fault but if anyone can throw anymore light on this matter before I order both PCB,s.

Perhaps just fit a push button switch in line, instead of the pcb, as does anyone bother with the waste tank level indicator??
frederic