Poor radio reception and extra wire

[spencetj]

I have just changed the Business RDS in my E36 for an old Kenwood head unit that I had lying around, and I am getting very bad radio reception. Its possible its just a bad connection, the tiny wire in the center of the aerial lead got broken during the refit and I had to try and solder it back onto the plug. The reception is fine on my driveway, but I found out this morning driving to work that it is pretty poor in many other places!

Is there anything special about the radio in the Philips Business RDS unit, like a booster or something, that I am now missing? There is an extra wire taped to my aerial lead with a small round connector on the end, which plugged into the back of the Philips unit, but there is no corresponding socket on the Kenwood. What is it, and do I need it?

Any help would be appreciated. Otherwise the local car audio place will charge me £20 just to look at it.

[hughjayteens]

Don't think they have anything special in there as I changed mine for a Becker unit and the reception improved markedly!
It sounds to me like a dodgy aerial lead - these can be replaced but it is a pain in the arse.
As a test, maybe try sticking the BMW unit back in to see if the reception is good again, as this will indicate if it is your Kenwood or the lead that is at fault.

[spencetj]

Thanks. Its worth a try to test the original head unit again, but its such a pain to try and get the connector off the back of it afterwards I am loathe to do it if I don't have to!

So I guess you didn't do anything with the spare wire, if you have one? I have had various suggestions, that it is either for aerial diversity or maybe a power or switch wire to activate the booster in the rear screen antenna. It looks more like a small aerial plug than a power wire I think.