Join Date: May 2005
Location: Uppsala, Sweden
Thanked 1 Time in 1 Post
car radios have two +12V inputs. One of them is supposed to be connected to a permanent source, this is needed to supply power for the station (and maybe other presets) memory, for the anti-theft-code option, and for running the radio when ignition is off.
The other input is supposed to be connected to a source that is only powered when ignition is on. That is, at least in normal cars. The radio is powered from this input while driving, and by this the radio can also "detect" whether ignition is on or off. Operation with ignition off is usually time-limited, to prevent the engine battery to be discharged. There are radios which allow this time limit to be adjusted or even deactivated.
I think that in your van the switch on the cupboard puts power from the leisure battery to the "ignition" input of the radio. That is at least how it is done in my Euramobil, where I have a similar switch.
If you want to completely disable the auto shut-off, then the easiest way is to both power inputs to the permanent source. Preferrably however, this permanent source should be the leisure battery and not the engine battery.
Euramobil Sport 585DS (C-class):