I bought a new headunit for my car and I can't get it to work i have the bose system so I got a wiring harness the part number was 70-1787 I believe I have everything wired together and plug it in and only the speaker on the drivers side door works I bought a Kenwood KDC-348U it has all the right rca plugs I'm not sure if its plugged in wrong or what the guy at weebee said the two red plugs are supposed to go together(he also drives an audi) but my red plug in the car doesn't fit the red harness and I can't seem to find another one I need some help from you guys since nobody else seems to understand my a4 I have been trying everyday for a week going through several harnesses and connectors if you know anything about this please share it with me this new radio shouldn't be this difficult

 

Sorry to hear about your troubles. I know that you're not the first one to have this problem with the 70-1787 adapter, so I would start by using the search feature on this forum and try to find other threads that discuss it in detail. If I'm not mistaken, I think the problem was that the wires on the 70-1787 were backwards, or some little modification was needed to make it work.

Good luck!

 

Ya it was a hassle thanks for the info I finally figured it out this morning and it works great now I just need speakers