hi,

just fitted a new stereo in my 1995 polo 6n but it isnt working. it powers up and ejects the disc and everything and when i press display it comes up with the time, but only for like a second and then goes off again. cant do anything else. at the back coming from one of the plugs of the car it has a short white wire that is not connected to anything...is this the problem? if anyone has any ideas i would be more than greatful.

Thankyou.

Is this with ignition on or off? you say a short wire, is this from the stereo wiring or from the cars iso harness? if it's from the car's harness, does the car iso plugs go straight into the stereo or do they go into a bunch of cables coming out the back of the stereo, if so what is on the stereos side of the white wire.

as above, with ignition on or off? also, check the constant and switched lives, always seem to be the problem on headunits...

the ignition is on, also tried it with the engine on. the white wire is coming from the wirering plug from the car. and yes they plug straight in.

Have you got another stereo use to test if its the car? Sounds like a faulty stereo tbh, if it powers up theres power.

yep tested a different one and its the same. just found a wire so i believe its been previously hooked up to a amp and probably a sub. should this change anything?

No, unless the person who wired the sub and amp was very un-competent.
Do you have a multimeter? or anything to test the wiring?
If so then take the head unit out and look at the plug, you should have both A and B on the diagram

so ignore 1,2,3,5,6 on a because they should not affect anything, but let me know if anything is plugged into either of 1.2.3 and if so what colour they are.
so your main 3 wires you want to test is 4 - switched ignition live/memory 7 - permanent battery live 8 - ground/negative
if you don't have a multimeter use a 12v bulb or appliance with some wires connected instead of a multimeter (i suggest an interior bulb with 2 wires attached each end and taped on)
First thing to do would be to check in general, so make sure ignition is off and connect a wire or push a prong into pin number 8, now connect the other wire/prong into pin number 7, if the bulb lights or you get a reading of 12v (ish) then you instantly know that your ground works and so does your permanent live, if not keep the wire/prong in pin 8 and remove the wire/prong from pin 7, now connect the wire/prong that came from 7 into 4, see if you get a reading/light now if so then that is your permanent live and is switched on some cars/stereos
repeat the above with the ignition on and see if you get a reading on the pin that you did not get a reading from before, if you do then everything seems fine

if you get no readings check your multimeter/bulb by putting a wire/prong on each battery terminal, if the multimeter/bulb is working then we can move onto checking your ground.
to check the ground put a prong/wire into pin 8 and then put the spare prong/wire onto the Positive battery terminal (+) (may have red wires/covers) you should now get a reading/light, if not then it seems like your ground is bad, just double check your connection into pin 8.
now to check your permanent battery live, again put a wire/prong into 7 and put the other end onto the negative battery terminal (-) (may have black wires/covers) if you don't get a reading check your connections, fuse and try turning the ignition on to see if you get a reading.
do the same as above for pin 4 and post back the results
Sorry if that was confusing but i have never owned a 6n so could not tell you specifically what you have to do, it might be helpful if you can post some pictures of the iso connectors, any wiring you think that should not be there and any modifications you can see, it might also be useful if you can post the stereo make and model so i can find a manual and check the order of permanent live and switch live.
also remember that someone could have switched the wires around so the pin numbers above could be wrong
Rough wire identification

Job: Colour: Thickness: Should be pin:
Ground black/brown thick 8
Perm live red/brown thick 7
Switch live red/brown thin/same as most others 4



At some point i will do a full post in depth with pictures showing how to test stereo wiring.