Where can I get a wiring diagram for a 1998 A4 1.8t. Im trying to install a new head unit and im seeing so many wires from the stock one and not as many for the new one thanks.

 

As long as you have the adapter harness (search "metra harness" on here), you'll be taken care of. You may have features like noise-sensitive volume control or other things like that, which will require wires, but which won't be included on your new head unit. Things like that will be eliminated with the new head unit. If you get the proper adapter harness, you'll be set, since each connector on the car's harness is unique relative to the others. This ensures that you can't accidentally plug it in wrong, and you'll have all the connections you need to hook it up properly.

 

This may be helpful:

https://www.audiforums.com/m_622462/tm.htm

Good luck, have fun!

 

^i know that link helped me a ton.also, if you look on the top of your stock head unit there's a sticker that shows a simplified wiring diagram.