No 12 volt power in caravan.

1}  connect  the  m-meter  across  the  battery  terminals

2}  check the  voltage  of the  battery

3}  watching  the  still  connected  meter  have  the  mains  connected

4}  the  battery  voltage  should  rise  sufficient  to  indicate  if  its  receiving  a  charge  &  thus  is  in  circuit

5}  if  not  you  have  a  disconnection  between  the  battery  and  the  12  volt  power  cct

6}  DISCONNECT  THE  MAINS  &  THE  BATTERY !!

6}  now  carefully  check  all  switches  &  wiring  connections

7}  Pray  a  lot  whilst  doing  these  checks  'cos  its  Sunday  &  also  your  time  is  much  cheaper  than  an  electricians 

Are you saying that nothing on 12volts is working?

A motor mover is normally wired directly to the unit with its own fuse and does not pass though the caravan 12 volt system.

You say you have a multimeter to check the fuse  -  have you checked to voltage leaving the battery?

If you have only checked the fuse it may be a duff battery or a bad connection on the battery terminals.

Are you saying that nothing on 12volts is working?

A motor mover is normally wired directly to the unit with its own fuse and does not pass though the caravan 12 volt system.

You say you have a multimeter to check the fuse  -  have you checked to voltage leaving the battery?

If you have only checked the fuse it may be a duff battery or a bad connection on the battery terminals.

Write your comments here...Should read :-

"Are you saying that nothing on 12volts is working when not connected to the mains?"

When you are towing a relay connects the caravan battery to the car 12 volt system, the caravan circuits are inactivated. If this relay fails to return to the non towing position, the symptoms you describe will be present.