Bongo Fury

I don't know if anyone can give me tips on this problem? I've got a drawer fridge Waeco CD 30 under the seat, that works beautifully when we're driving along. However when we stop, I can't get it to work either when on hook-up, or running on the leisure battery alone. At night I can hear the fridge kick in, then it stops within 3 seconds, then kicks in again 10 seconds after that, only to stop again. And so it goes on.
Any ideas what the fault could be? I'd suspect the leisure battery, but why wouldn't the mains hook-up keep it going?
Many thanks.

Yes the Low Voltage Cut out is operating.
Fridges and other similar items designed to work all the time will monitor the voltage at the fridge and if it falls below about 11 volts will switch off to avoid damaging the battery that is supplying it. Hence you hear the cooling fan come on (low current draw), then a few seconds later the compressor motor tries to start, it draws a lot more current especially during starting, hence the voltage falls and it trips out. It could be the that the LB isn't fully charged, it could be that the wiring to the fridge is inadequate or it could be a poor connection at a connector or fuse. Try checking all connection points between fridge and battery, fuses, switches etc. If you have a meter check the voltage at the battery and see if it is dropping when the fridge tries to come on, if it doesn't then its probably a poor connection dropping the voltage in the wiring.

Many thanks Geoff. I'll check all that.