12 VOLT SUPPLY peugeot boxer 1998

I bought a new 12 volt leisure battery this winter, worked fine to start with. Now 12v lights will not work without mains. Have just returned from Scotland 300 miles lights would not work  when got home. Have checked fuses above rear door 6 number all ok. When on 230volts supply green charging light is on, on panel above door and switch is down on 12 volt supply. I have a Talisman 1998, any suggestions will be appreciated. Lew Barlow Wolverhampton.

Lew,
Under the drivers seat there should be a 30amp blade fuse tucked away almost out of reach. Pull it out and have a look and replace if required.
Note of caution- if your underseat battery and electrics are anything like my '98 Harmony you will need to be double jointed and be able to work by feel as the fuses are up against the offside of the seat base. Have a few spare fuses to allow for 'droppage'  as pulling them out is easier than plugging them back in.
I had a similar problem and this time it needed the 5 pin relay to be replaced. My habitation guru also moved the 30amp fuse holder to a more accessible position.
Hope this helps.
Terry