A4 B5 1998 - Concert H/U replaced - BUT...
 

OK SO... i bought a new H/U for my car. I made a "key" from a piece of flat hard plastic found on some sign i had laying in the garage.

Checked the Pin assignments on the back of the Concert and unplugged, Then i used a multimeter to test power on and power on with ign. off. Then checked for speaker operation. I plugged new loom ends, which were soldered, straight into the original loom. Then i hot glued them in place. I found that the yellow plug with six points, for rear powered speakers, needed a power to the left center pin so i ran this and then plugged the new radio in - WAHLAH!!! Everything worked.

AHHHH BUT... with it being Xmas i couldn't find the trim for the gaps in the dash (will get them shortly) and i couldn't find an aerial adapter. NO Sweat - the MAIN reason i got the new H/U is to play MP3s and my music DVDs - radio is not a major issue for a few days.

BUT (again) even during DVD/CD/MP3 i get engine static when it is running. Is there something i missed? I "fashioned" a make-shift aerial adaptor which works. Now even with this in or out i get "buzz". Ok so there was a ground plugged to the concert body which had no place to go on the new unit. SO i tested with it against the new body and earthed - no difference.

Any ideas? Thanks in advance.

Well all sorted now. I have the trim in the dash and got the aerial adapter. PERFECT!!

So what about the static "buzz"? Ok that is also sorted. On the yellow plug with 6 points - for rear speakers - i didn't put the earth for the speakers in. I initially only plugged in positive and they worked - SO, i assumed the car had a common speaker negative so I didn't fuss.

While fitting the trim and adapter yesterday i thought while i am finalizing the H/U install let me put the speaker negatives where they should go and the static buzz is now gone.