Should you need to disconnect the battery, on some cars you can connect a memory saver to the cigarette lighter socket which then retains the ICE memory.I've just bought a R75 Contemporary 2005, which has a CD413X fitted. It works ok but I do not have the code. Bearing in mind that I may have to disconnect the battery for some job or other, I'd like to have the code available. Is there a preferred way to get it? (and how is the head unit removed, presuming that I'll need the unit's serial number? Do i just use generic wire clip things on each side?
Should you need to disconnect the battery, on some cars you can connect a memory saver to the cigarette lighter socket which then retains the ICE memory.
It will work best on cars in which the cigarette lighter is not connected via the ignition i.e. cars that allow the *** lighter to be used without the ignition on: on those that have to have the auxilliary or ignition turned on, you need more current going in to power up all the other things.
I have never tried any of these but in particular would be a bit sceptical about the ones that use a 9 volt battery, there is no guarantee that 9 volts will be near enough to the usual 12 volts.
What I have done is connect a laboratory power supply to the battery terminals before I disconnect the battery, which means the memory supply is independent of the battery. You could try a battery charger instead of a power supply, but crude battery chargers can give out high voltages when they are not charging a battery.
If you need to disconnect the ICE from the car, there are probably no other options than to have the code itself.