the blue wire is like a remote cable...the whole amplified aerial is a tiny amplifier in itself so it needs to be powered up, hence the blue wire. if you have an aftermarket unit like say a sony with its own power loom, then it would patch onto either the remote or more preferably, the electric antenna out "ATT"
failing that and its the original radio, you would have to look at the radio pins at the back if there is an electric antenna output.
Do not patch it into an ordinary power supply, there are risks of damaging it that way despite the remote and att sending out 12v supplies also.
basically, you only want it to work wen the radio is on and the "tuner" function is activated as that is the only time you aerial will come into play. Remote is always on so long as the head unit is powered up which is the next best one to use but the "att" is the better one to use!
If it is any other radio but still has its own power loom, then you would need to patch it into the "blue" wire which may also be the "blue/white stripe" wire. but if there are both on your loom "blue and blue/white" then just patch it into the plain blue one!
Hope this helps. if you stil struggle then reply with the brand of radio that you have and i shall give you a more accurate answer of where it needs to go!
