k11 radio

hello all / I have a 2002 k11 micra with a radio that works but with a u/s screen / I also have a similar k11 as a donor car with a perfect radio / I have no codes for either but I want to put the good radio in my good car / I have done some experiments / if I disconnect the battery on either car I do not loose the as when the battery is reconnected the radios both work / I have taken the radios out of the dashboard but left the plugs in place / on the back of both radios there are three plugs/sockets / one is the aerial and there are another two with a few wires connected / if I have the radio playing and pull the large plug out the radio goes off and when reconnected it continues to play / if I pull the small plug out the radio continues to play but if I then switch it off when I switch it back on it says wait on the screen / if I then switch it off put the plug back in then switch it on the radio will play / from all this I conclude that the large plug carries the power and speakers while the small plug carries the signals from or to the security unit / my question is this / before I go any further is there any thing that I can do to get the radio working without a code as It once that you have got it going you can pull out the small plug and it will continue to play until switched off / it seems a bit complicated but read it a few times and tell me what you think / thank you
All you can do is have the working ones code wiped and reset as a new unit at Nissan. That small plug at the back with the black and white wire is the security one. With a blank/ new stereo the code gets automatically entered. Other than this you can see about trying to swap the screens over. Trouble is that they're carbon ribbons and heat bonded I think to the main board. It's a while since I had one apart. Most ppl usually just put in an aftermarket one with all the bells and whistles. It's usually cheaper at around £70 for s half decent one.
Those other 4 wires go to the rear speakers. Where abouts are the rear speakers I hear you ask? Well there is a parcel shelf you can get (eBay) that has 2 quite good speakers in it. The wiring for this upmarket shelf is hidden behind the carpet on the right hand side of the rear wheel arch. Unwrap the grey stowage tape and it plugs into a little hole just under the plastic trim near the rear shelf right hand hinge. By the way, even though the wires are in that plug of the stereo the stereo itself doesnt output to them. So you still need an after market one or a 4 speaker uncoded Nissan one.
hello again / I have a small card that came with the donor car / the good radio one / it has on it radiopass Nissan and three boxes / one says type/ model bp6340 / the middle one says serial-no 27912023 and the end one says safety-no 8138 / could this be the code for this radio / 8138 / thank you
hello / thank you for your second reply / I am grateful for any info. as this is the last car I intend to have / I have had three micras and really like them but mine has now done 104000 miles / that is why I got a donor car / it has only done 41000 miles but has failed the mot due to rust / I will change the engine when required / I live on the Shetland isles and cars fall apart here due to the salt air / I have only been here 4 years so mine is o/k but I will keep on top of it / I am 76 so it gives me something to do and I like working on old cars / I have sent another message while you were sending you second one / thank you