kettle plugs

[silvermod]

looking to see if i have the connection for cd changer(i haven't) found in same area 2 kettle type plugs one with all 3 pins and one with just the 2 bottom pins any ideas please what these are for
v reg1,8 estate with tow bar fitted

[silvermod]

put a meter across the plugs one is dead i think but the other gives a 12 v output
i assume someone has taped into the cucuits to power something or other will have to keep an eye out for 12 volt goodies with a kettle type socket