leisure battery

Hi

we have a 20 yr old peugeot boxer symphony, just acquired. My question is, will the leisure battery charge automatically when driving or do we have to have the battery charger switched on too? If we wish to have the fridge on too, whilst driving, should we have the 12 volt switch of or on.?  The red light indica ting that the fridge is on does not appear to be working. We had an old Eriba before, without a battery charger, and the leisure battery would charge automatically...and fridge stay cold... now it is more complicated.
Also....can we over charge it when plugged into mains and battery charger on? We are clearly not technically minded .....nor spring chickens!

On older vans (i.e. 80's and early 90's) it would not have been unusual for a mains charger to be optional, but by 2000, your van will have had both a split charge facility (to charge the leisure battery while the engine is running) and a mains charger to charge it when on EHU.

Both will normally be trouble-free, but if it has been on a forecourt for a while or sat unused for long for other reasons, you may find that the leisure battery has been allowed to get flat, and then you can have problems with blown fuses.

Typically you should not need the main power control system to be turned on to run the fridge on 12V with the engine running - you should only need to switch on the 12V switch on the fridge itself.

The original charger fitted to that age of conversion won't be very sophisticated, but it should be fine to be connected for days at a time without overcharging the battery. It's probably best not to use it for long-term battery maintenance though. Different people solve this in different ways, but one method is to set up a timeswitch on the EHU when you're at home, so that it only charges for (say) one day a week while it's unused and in storage. Solar is of course another way to do it.

my old medallion fridge had an illuminated  rocker switch on the fridge for the 12 volt system , the  red indicator bulb blew but the switch still worked the fridge but without illuminating the switch . the said switch was slightly thiner than any I could get , so to fix it I dismantled the original and replaced the bulb from a slightly larger one . a bit of a fiddle with some solder but I didn't have to modify the fridge panel .

Thank you all for thoughts and replies. How would I know if the leisure battery is charging whilst driving??

The simplest way is to measure the leisure battery voltage when the van is stationary and off EHU - start the engine and you should see the voltage jump from around 12.6V to around 14.4V (very approximately).

How you do that depends a bit on how the electrical system is configured - some control panels of that age had a leisure battery voltage meter on them. Otherwise you can get a plug-in digital voltage display that plugs into a cigar lighter socket (if you have one that is supplied from the leisure battery). Failing that, digital multimeters are relatively cheap.