I just bought a green mica 97 A4 1.8 turbo for my family as our sporty 4 door saloon. I had a little trouble getting home from the previous owner because it wouldnt start all the time. After pounding the starter a couple times with a hammer and a punch, it started right up and we drove it home perfectly. After testing the starter(which worked when jumped to the battery) I concluded the problem is somewhere along the wire leading to the ignition switch or the switch itself(no blown fuses on the driver's side, relay is good). So until I can order new parts, I tried wiring a switch to the starter so at least we can start driving it around. Problem is, I think I might have mixed wires on accident yesterday while trying to get the starter to work... The gauges were going nuts, lights got really dim, and there was some mechanism at the throttle body that was moving and clicking. After wiring up the switch, the starter works and the car starts right up, but it loses its electrical charge immediately from a full 12V down to 7.3V in a matter of 15-30 seconds... How do I fix this? Im worried I might have seriously hurt our A4. Please help

 

sounds like the problem is still the starter itself. there is usually a solenoid within the starter. if its burned up or shorted, yes a hot wire and switch two it can start the car but it can cause similar issues to what you are describing. basically just shorting out circuits. pull the wire and wait to drive it until you can get a new starter in there if at all possible.

as for any major damage, nah. just check the fuses, to make sure none of them went boom on ya.

oh and if you can get the starter off usually parts stores can check them for free on a bench and pin point exactly what went wrong with it (if its bad that is)

hope i was of some help.