Audio Systems: Audi 100 radio Power, fuse box, bose speakers

Question
I just purchase a 1992 Audi 100 for my son to drive.  This is the first car I have owned where the radio stays powered on even with the key off and out...The radio is a Blaplunk with powered Bose speakers.  Hard to find any information on this; however, I'm told that there is some sort of resistor which is not working and this should not work this way...any advice?

thanks,  bernie

Answer
Hi ya Bernie,
This one crops up a lot on German cars, I had an Audi 80 sport, bit older than yours by 20 years, but a good car.
German cars up until recently didn't have an ignition feed to the radio so they were on all the time. on the back of the radio are two blocks called ISO DIN plugs these are industry standard now. one has the 8 speaker wires and the other the power leads, take a wire from the output side of any ignition fed fuse in the fuse box such as cig lighter and connect it to the wire next to the earth wire as in the text below, the radio will now switch on and off with the ignition.

Power block viewed from cable side

Phone mute (white),/   n/c, /      ariel & amp (blue), /ignition (red)

N/c, / 12vlive, (yellow or orange), / lights, (various colours),/ negative (black)

The third, usually top, block is for accessories such as cd changers
have fun, Peter